Ellen Reed sent an email to her son's preschool two years ago, asking parents if their children would play with her son.

Her son, Robbie, is now 6 and high-functioning on the autism spectrum. He has had intensive therapies since he was diagnosed four years ago. One of his therapists suggested scheduled, supervised play dates to help reinforce social skills.

More than half the parents from his preschool class in suburban St. Louis volunteered to help out, and Robbie had regular play dates with classmates during the summers.

"It's been incredibly helpful," Reed said.

Playing with another child is actually pretty complicated. There are lots of social cues to pick up on and unspoken rules to follow. There are expectations about taking turns, sharing, asking questions -- things that may come easily to most children by a certain age, but require a great deal more practice for children with special needs.

Autism, in particular, which is characterized by difficulty in communicating and forming relationships with other people, can make friendship the hardest skill to learn.

Kim Stagliano, a Connecticut mom of three autistic daughters, has seen how isolating this can be.

"My girls do not have friendships with peers that aren't facilitated by an adult either at school or in therapy or at a camp," she said. The differences that set her children apart in elementary school widened as they moved on to middle school.

"By high school, it's really a chasm."

Her daughters are 14, 18 and 20. They have never been invited to a sleepover. They haven't been invited to a party since grade school.

They have nice interactions with other peers. "But that's not the same as a social life," Stagliano said.

She remembers a moment when her middle child, 13 at the time, stood at their front doorway watching a group of girls play outside in the neighborhood.

"Gianna wants friends," the girl said, referring to herself in the third person.

"It's a kick in your gut," Stagliano said.

She asked her daughter if she wanted to go outside.

"We can ask them if they want to play," she said to her daughter.

Gianna said no.

The situation was too intimidating.

Learning to initiate a conversation, engage and interact with a person is like learning a foreign language for autistic kids, Stagliano said.

"It's about breaking down social interactions into tiny, tiny steps, into things that most of us do not have to think about," she explained.

While there is much more awareness of autism than there used to be, many people may be unsure of how to encourage a friendship between a child who struggles socially and their own child.

How should the parent of a typically developing child attempt to include a classmate who appears to have few friends?

"Invite the child," Stagliano said. "Send the invitation." Then, call the parent. Ask if the child is on a special diet. If the invitation is for a birthday party, ask if the parent would mind staying with the child.

When Stagliano's children were invited to parties when they were younger, she would tell the hosting parent that she would bring her child's snack or cake since she was on a special diet, stay in the background during the party to make sure things were going smoothly, and leave when it looked like her daughter might be getting tired.

"Don't be intimidated," she said. "The mom will be so happy to get an invitation."

Reed, Robbie's mom, said her hopes and dreams for her child are the same as any other parent's.

"Will he be able to do well in school, go to college, get married and have a family?" she wondered. When he was diagnosed at 2, "I didn't think any of that was an option." Now, "he's doing so well, I think those options are distinct possibilities."

She expects her child will encounter many kind and generous children who will look out for him, as well as some bullies who may pick on him.

Maybe the skills he learns from his weekly, highly structured play dates with his peers will help him learn the social skills he needs to survive. She hopes to be able to continue them for as long as he needs.

"Maybe when you are 17, you shouldn't have your mom scheduling your play dates," she said. "But if that's something we need at the time, I'd totally be doing it."

I hid my face behind two dozen white and red roses as I rang the doorbell.

I held my cellphone to my ear in the other hand, asking my mother about her weekend plans.

"Hold on," she said. "There's someone at the door."

She opened the door.

"Happy birthday, Mama!" I said, having flown in to Houston late last night for this surprise. She screamed loud enough to frighten a few neighbors and grabbed me in a tight hug.

This was just the start of the weekend surprises for my parents.

My mom turned 65 in March. I wish that meant she retired from her job as a sales clerk at Macy's, but like so many other Americans, she will need to delay retirement at least a year. My father, in his early 70s, went back to work as a full-time substitute teacher a couple of years ago.

I've never heard them complain about having to work past retirement age, although I have wished I could make things easier for them since they've spent their lives raising six children. In more than 40 years of marriage, I remember them taking a vacation alone together -- not to visit family or friends -- once.

My father had won an award as the top salesman at his car dealership, which sent them to Bermuda for a weekend. That was more than 25 years ago.

My siblings and I decided this would be a good year to surprise them with a gift they would never give themselves. We settled on a cruise to Alaska.

The gift was a big risk. They are scared of cold weather. In Houston, 50 degrees is cold. They have never taken a cruise. They get worried about navigating unfamiliar places.

But, they love the beauty found in nature. We wanted to push them a little out of their comfort zone.

Their sacrifices in our childhoods opened up the world to us as adults. Here was a chance to do the same for them.

We decided to present the "big reveal" at my mother's birthday party the next day by having them unwrap a series of clues.

There were six boxes to open. One from each of us. One by one, they found a plastic gray wolf, a headband with antlers, a jar of maple syrup, a toy plane and a ship.

Of course, they guessed it.

"We're going to Alaska," my dad said.

At the moment, they seemed touched by the gesture. Later on, each of them privately approached one of us children, trying to get out of the trip or have it delayed.

We held firm. We reassured them all the details had been arranged and sent them off with a big binder of everything they needed to know.

Meanwhile, all of us held our breath. They were only gone for five days, but it felt much longer.

I talked to them as soon as they returned.

"It was so majestic and beautiful," my dad said. He pointed out that most of the people on the cruise were middle-aged or seniors.

"Older people really enjoy it," he explained. "They feed you the best food on the face of the earth. They really take care of you like no one would."

My mother, who is notoriously particular about food, agreed.

"I loved it," she said. The ocean, mountains and trees were breathtaking.

"We got sunshine," she said. "No clouds, no cold."

What a relief.

They made friends with a traveler from Canada, an elderly South Korean woman, who said she prayed for good weather after meeting and talking to my parents.

Bless that woman.

It didn't surprise any of us that after this experience, my mother decided that her entire family -- children, spouses and grandchildren -- needed to take a cruise with them next.

It's that parental instinct to immediately want to share the best things you experience with your children. My father said the minute they landed at their port in Alaska, my mother became a woman on a mission.

"Can you believe she spent all day in Alaska shopping for her grandkids and children?" he said. "As soon as we reached there, that's all she thought about: her grandkids."

He laughed.

"Boy, that kind of love is unbelievable."

It really is.

It's best to steer clear of confrontation in the carpool lane. But it's harder to hide the silent judgment in our eyes.

A few days after my son's birthday, I ran into the parent whose son had been a no-show at the party. Her child loudly reminded her that she failed to bring him because she promised him a different outing. He then said, again audibly emphatic, that they didn't end up going anywhere.

The mom tried to avoid eye contact. I tried to pretend the child had not had this conversation right in front of us. The entire exchange was awkward and seemed so easily avoidable: Had she called or emailed in advance, or even apologized on the spot, I would have understood. Family schedules are hectic and packed, and we've likely all experienced an etiquette fail at some point.

As it is, the entire dance of invitation and response has become trickier. Fewer people bother to respond to invitations at all, while the ease of digital invites has escalated the number of events we are asked to consider.

Earlier this year, British parents sent their son's 5-year-old classmate in Cornwall an invoice and threatened to sue for failing to show up for a birthday party. That's ridiculous, but the frustration with the lack of manners is understandable.

"The rules are still the same," said Melenie Broyles of Etiquette Saint Louis. "It is courteous to respond, so hosts can plan a party," she said. Ideally, potential guests should respond within a day or two of receiving an invitation.

"People do not RSVP like they used to," she said. "People wait until the last minute to respond. We don't even consider the consequences of responding last-minute or not at all."

She estimates the rate of response to formal invites to be less than 50 percent until hosts start calling to follow up. Email services such as Evite have a greater response rate because they allow the host to send reminders, and indicate whether the recipient has viewed the invitation. Plus, it takes only the click of a button to hit "yes," "no" or the unhelpful "maybe."

"Being a no-show is unacceptable," writes Emily Post. Chronically failing to respond or show up can derail friendships and alienate relatives.

But the constant stream of invitations can also be difficult to manage. The Facebook invite has elevated the casual get-together or play date into an Event. Then there are public events to which a person's entire "friend" list is invited, which do not require the same diligence in response.

I've received text invites to parties traditionally requiring gifts, along with the steady stream of invites to events in which the hostess is selling a product. Those do not merit priority in response.

But the guideline to check a calendar within a day and respond in some manner is a good habit to instill in our children.

If the RSVP is dying, we should attempt to revive it.

"I think many families are just trying to survive," Broyles said. "But once you realize (you've missed an event or failed to respond), an apology is always appropriate. People appreciate that you acknowledge it."

Oftentimes, it's not until a person has taken on the financial investment of throwing a significant party such as a wedding or similar formal event that they appreciate the importance of a timely response.

A poster on a website for brides-to-be vented about the nightmares of chasing down wedding RSVPs and dealing with odd guest responses, such as writing in a number of guests much greater than the two who were invited.

"I think this is all normal, which sucks, but it's true. I know before I got married, I was a late RSVP'er too. I think you don't realize how important it is until it's you," she wrote.

Broyles advises hosts that if someone doesn't respond, they need to follow up and make sure the guest received the invitation.

In the late 1800s and early 1900s, when invitations were often hand-delivered, the prompt of an RSVP on an invitation was considered unseemly.

"Well-bred people do not use R.S.V.P. on dinner invitations. Your guests will have sufficient politeness to reply without having their attention abruptly called to it," notes "Mrs. Rorer's New Cook Book," first published in 1902.

"Whether the invitation is accompanied with the request for a reply or not, all thoughtful people will recognize the propriety," according to Agnes H. Morton's "Etiquette," from 1919.

That was when all replies, whether regrets or acceptances, were expected to be handwritten and delivered. Anything less was considered vulgar.

Nowadays, technology has made responding easier than ever, which should raise our expectations of manners -- not lower the bar even further.