DEAR ABBY: Do you have any information or advice on how to talk to my 12-year-old stepdaughter about sex? I have a pretty good idea about where to take the conversation. I don't plan to make it a big deal -- not so serious as to scare her, but not too lighthearted either. You never know what kids are saying about it in school these days. I want her to know the door is always open should she need to talk. (My mother did that with me, which I appreciated.)

If you have any pointers or reading material suited for her age, that would be great. -- STEPMOM IN TEXAS

DEAR STEPMOM: I'm glad you are opening up the subject because "the talk" with your stepdaughter should have started long ago as part of an ongoing discussion. For a variety of reasons, young people today mature much earlier than they did years ago. She should be told that, if they haven't already started, the changes that will take place in her body are normal and nothing to fear.

As for reading material, my booklet, "What Every Teen Should Know" can help you to start that conversation. It has been distributed in doctors' offices and used to promote discussions by educators and religious leaders, as well as parents who find it hard to discuss these topics with their children. You can order one by sending your name and address, plus check or money order for $7 (U.S. funds), to Dear Abby Teen Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. Shipping and handling are included in the price. You should review it before starting the conversation so you will be prepared in advance to answer her questions. The more information you can give her, the better prepared she will be to make intelligent decisions in the future.

DEAR ABBY: I am a 25-year-old, well-educated woman, engaged to a wonderful man. Although we don't plan to wed for another couple of years, I have a question on my mind. Neither of us is traditional or religious. What should I do about my name?

My fiance would be honored if I took his name, but wouldn't be insulted or hurt if I didn't. For a long time I had thought that hyphenating would be an appropriate solution, but the more I consider it, a long double name on everything I will have to sign might become an inconvenience. I don't dislike his last name or have strong feelings against taking it, but I like the name I have now. Part of me likes the idea of always carrying it.

Since children are not going to be part of the equation, there's no risk of confusing them or their teachers. What do other young couples do? I would love an outside perspective. -- NAME GAME IN KANSAS

DEAR NAME GAME: It is no longer unusual for women to retain their maiden names after marriage. Many choose to do it because they have become established/successful in their careers, others because they want to maintain their identity as an individual.

Some women solve the problem by using their husband's name legally and retaining their maiden name professionally. Others use their maiden name as a middle name and their husband's last name. Please don't worry about this; you have time to make your final decision.

DEAR ABBY: I am a partially disabled person in my 70s. Because of arthritis in my spine and hip, I'm able to stand for only a few minutes and walk only 20 to 30 feet. When I know I am going to be someplace that requires more walking or standing, I use my wheelchair.

My question is: How do I reply to strangers who ask me, "Why are you in a wheelchair?" One lady said, "Oh, is it your knees?" I feel the questions are rude, and I shouldn't have to explain my medical status to people I don't know. I try to mumble something about not being able to stand for long periods, like waiting in line. But I'd really like to respond with a funnier, more flippant reply if I could think of one. Any suggestions? -- TRAVELING BY WHEELCHAIR

DEAR TRAVELING: Try one of these "flippant" possibilities: "It's nothing I usually discuss in public, but it's contagious!" Or, "I broke my tailbone dancing at the Bolshoi." Or, "Just lazy, I guess."

However, joking about a medical condition isn't funny. So perhaps you should reconsider and just be honest.

DEAR ABBY: I recently was invited to a surprise 50th-birthday party for my twin sister. Her husband had a family dinner that included all my siblings.

When my brother-in-law invited me, he said my sister didn't want a big party, but he wanted to celebrate our birthdays with this special dinner. I was delighted to attend, but I must admit I was a little hurt when the celebration turned out to be strictly for my sister. My name wasn't on the cake, and only she blew out the candles and opened gifts. (I did receive two cards.)

I know the party was given for her, and I was a gracious guest, but as her twin, I felt awkward and ignored. Am I being overly sensitive, or were they just rude? -- TROUBLED TWIN

DEAR TROUBLED TWIN: Oh, my. I don't think your brother-in-law was being rude. But in light of the fact that you and your sister were womb mates, you were treated with incredible insensitivity.

DEAR ABBY: I'm in a sticky situation. My husband, "Chester," can't stand to eat meals with my dad. It's never bothered me, but Dad sometimes "smacks" or talks with food in his mouth. It drives Chester crazy. We visit them every week and meals are always involved. What do I do? Should my husband just get used to it? We decided to ask you for advice before we do anything else. -- IN A PICKLE IN TEXAS

DEAR IN A PICKLE: Have your mother talk to Dad and "suggest" that their son-in-law is used to more formal table etiquette, so would Dad please make an effort to not chew with his mouth open when the two of you are visiting. I can't promise it will do the trick, but it may make your father more conscious about what he's doing.

DEAR ABBY: I have just learned that my sister's husband of 35 years (I'll call him George) hasn't filed their personal income taxes going back a number of years. This has caused a lot of stress and anxiety for my sister, who recently underwent breast cancer treatment. Apparently, he hasn't filed because of his inability to organize. (His family has denial issues.)

Their professional tax preparer has met with both of them and tried to work out a step-by-step program, but George consistently fails to meet the deadlines. I love my sister and want to be as supportive as possible, but I'm unsure what I can do. I have advised her to seek therapy. She has copies of business-related documents relating to the unfiled tax periods, but not enough information to file on her own.

On top of everything else, she has several relationship issues with her children that are causing her grief. What else can I do? -- HELPLESS BIG BROTHER

DEAR BROTHER: Failure to file one's taxes is a federal crime that could land your brother-in-law and sister in the slammer. That's why you should urge your sister to do something she should have done years ago -- take over the family finances.

She and her husband may need more help than their CPA has been able to give them. A group that I have mentioned in my column before is the National Association of Enrolled Agents (NAEA). These are tax specialists -- some of whom are attorneys and CPAs -- who are specifically licensed by the Department of the Treasury. Tell your sister to contact an enrolled agent by visiting www.naea.org. TODAY.

DEAR ABBY: I recently moved in with my boyfriend, "Teddy." We are both in our 20s. Five years ago, he married his high school sweetheart. Two years later, she cheated on him and left. Teddy and I have talked about the situation countless times. I know he doesn't love her anymore and cares for me a lot.

Abby, I lose sleep over their relationship. I can't stop thinking about how she left him -- not the other way around -- and if he hadn't caught her cheating they would still be together. I Google her to see if I can find out anything about them. I check her social media sites multiple times a day. I know I'm being ridiculous, but I'm obsessed with her!

Teddy is such a caring man, he tells me everything I want to know, but my obsession with her and their relationship is starting to get to him. I don't want to lose him, but at the same time I wonder if I will have to leave because I can't get over their marriage. What should I do? -- OBSESSED IN OHIO

DEAR OBSESSED: There's an old saying that applies to your situation: One man's trash is another man's treasure. Your boyfriend's ex didn't recognize what a prize she had, fouled the nest and threw him away. How lucky for you that she did.

I can understand your being curious about her; what I can't understand is your compulsion to stalk her online. What she's doing these days has no effect on you or your relationship with Teddy. If you keep this up, you will drive him away. If you can't stop, find a licensed mental health professional who can give you the tools to overcome your insecurity. It will be money well spent.