DEAR ABBY: I am a 12-year-old girl and have a 10-year-old brother with autism. At school there are many kids who have special needs, and I try my best to befriend them.

A large number of students are unbelievably cruel to these people. They call them names and make fun of them right to their faces. Sometimes they don't do it in front of the person, but I also think it is very rude to talk about people behind their backs.

When I see or hear it happen, I would like to be able to say something to help them understand that what they are doing is not acceptable. What should I do when I am caught in these situations? -- TRYING TO MAKE A DIFFERENCE IN OHIO

DEAR TRYING TO MAKE A DIFFERENCE: People who ridicule others because they are physically or developmentally disabled sometimes do it for attention because it makes them feel superior or because they don't realize the damage they are doing.

One way to correct the perpetrators would be to speak up and say you don't think what they are doing is funny because you have a brother who struggles every day with the challenges of autism. You should also talk to a counselor or the principal of your school, describe what has been happening and suggest that the student body could benefit from sensitivity training regarding discrimination, which is offered at many schools.

DEAR ABBY: My sister-in-law was unhappy in her relationship, so my husband and I offered to let her stay with us. We moved her and all her stuff into our home. We even kicked our 3-year-old out of his room so she could have privacy.

She stayed with us for two nights, then went to her mother's. She was gone a week, then came back and spent one night. Then she returned to her mom's for two weeks. Most of her things are still here, but she hasn't said she's living with her mother permanently.

Do I still have a houseguest? I'd like to give my son his room back, but I don't want to be rude to my possible guest. -- POSSIBLE HOSTESS

DEAR POSSIBLE HOSTESS: Your little boy needs his room back! Unless you are ready to establish some boundaries, your sister-in-law could bounce back and forth indefinitely. It's time for you and your husband to talk to his sister and his mother and determine where his sister plans to nest, because it is unfair to use your son's bedroom as a storage locker.

DEAR ABBY: Several months ago, my husband -- whose eyesight is fading rapidly -- was forced to depend on a cane indicating that he is blind. Since then, we have encountered many individuals who have no idea what a red-tipped white cane means.

We have heard people say things like, "Isn't that fancy!" or, "I love the way you decorated your cane for the Christmas season."

Abby, please inform your readers that a white cane with a red tip is not a fashion accessory or a personal whim. Its purpose is to allow a vision-impaired person to move around independently. Vision impairment also affects a person's balance. People have brushed past my husband, bumped into him and expressed annoyance because his slowness held them up.

I'm sure a "word to the wise" from you would make a decided difference. -- NANCY IN LACONIA, N.H.

DEAR NANCY: I'm pleased to help you spread the word, and you have described the situation very well. Allow me to add this: It's rude -- and can be dangerous -- to touch a stranger without permission. Not only could it cause the person to react in a hostile fashion, if he or she is blind, it could cause a nasty fall.

DEAR ABBY: I was the only person working out in the gym at my apartment complex the other evening when a man, presumably another resident, came to the front door. To enter, you must swipe your access card on the keypad.

He apparently did not have his access card with him and sat outside the door waiting for me to let him in. Because I was working on a cardio machine and trying to maintain my heart rate, I didn't want to interrupt my workout to open the door. He eventually tired of waiting and left.

Should I have stopped and let the person in the door? Or should he have gone back to get his access card? -- CARDIO CARRIE IN GEORGIA

DEAR CARRIE: While it would have been nice of you to let the man in, it could also have been dangerous because you were alone and the person was a stranger. The security door was put there for a reason, and I find it interesting that the man did not go after his entry card and return. The fact that he didn't suggests that he may not have been a resident as you assumed, and you may have dodged a bullet.

DEAR ABBY: I have been dating/engaged to a wonderful man for almost a year. He was recently deployed for a 14-month tour of duty in Iraq with the Marine Corps.

We planned to be married in August while he is home on R&R, but a few days ago he asked that we postpone the wedding until next February when he is stateside for good.

He was gung-ho about our nuptials until a few days ago, when he requested that we wait. I'm confused because all he talked about was getting married and now it's a sore subject. -- MARINE'S GIRL

DEAR MARINE'S GIRL: Having never met or spoken to your fiance, I can't explain what is going on in his head. However, active duty in a war zone is extremely stressful, and his change of attitude may be related to that.

It takes a strong woman to be married to a man in the military, so be patient, stay positive and let him know that you'll be there when he comes home. Do not pressure him for answers right now. Continue to be as supportive as you can. When he returns in August, you two can have a heart-to-heart talk about why he wanted to slow things down.

DEAR ABBY: We recently celebrated my stepdaughter's 40th birthday. After dinner I placed the birthday cake, along with the knife, cake server, plates and forks, in front of her. We sang "Happy Birthday," and she blew out the candles.

Shortly afterward, I realized she was not cutting and serving the cake, so I asked if she wanted her father or me to do it.

I was raised with the idea that the person whose birthday it is should serve the cake to those celebrating with her (or him). Now I have begun to wonder, what is the proper custom regarding who should cut and serve the birthday cake? -- CURIOUS IN SAN FRANCISCO

DEAR CURIOUS: I'm not sure there is a rule of etiquette regarding who should serve the birthday cake. It's really up to the individuals involved, and the custom can vary from family to family. In your case, when you saw that your stepdaughter wasn't cutting the birthday cake, you did the right thing in asking her if she would like you to. That's what I would have done.

DEAR ABBY: I am a 30-year-old woman with a baby due in June. This will be my parents' first grandchild, and they are over the moon.

I have a full-time job, but I live with them because I go to school part-time. After paying tuition and other bills, I can't afford to live on my own. Moving out is not an option right now.

The problem is my father's drinking. He starts early in the afternoon and continues until bedtime. He is retired and doesn't think he has a problem.

I mentioned to my mother tonight that if he thinks I will let him hold my child after he's been drinking, he has another think coming. Mom informed me that it is none of my business! When I said it is my child and that makes it my business, she just nodded. She doesn't know what to do about it, and I don't either.

I love my dad, but I have to be a responsible parent, and that means putting my child's welfare first. I want Dad to be a part of my child's life, but not when he is in a stupor every night. How do I tell him that his drinking will affect his role as a grandparent? -- EXPECTANT MOM IN WISCONSIN

DEAR EXPECTANT MOM: You tell him in plain English, preferably in the morning while he's still sober, and do not allow yourself to be dissuaded. If necessary, make outside arrangements for child care if you cannot be present to supervise because it appears your mother has no influence over your father's actions. I'm sure you are a good daughter, but in your new role as a parent you MUST protect your child because he or she will be completely dependent on you.

Both you and your mother could benefit by joining Al-Anon, an offshoot of Alcoholics Anonymous that supports friends and families who are affected by a loved one with a drinking problem. It is listed in most telephone directories or can be contacted through � HYPERLINK "http://www.al-anon.alateen.org" ��www.al-anon.alateen.org� for the location of the nearest chapter. Please don't wait. Because your dad is in denial, you are going to need all of the support you can get.

DEAR ABBY: My father has always been a caring parent. Even after he and Mom divorced, he was there for my sister and me.

A few months ago, I found out that we may have a half-brother from an affair Dad had with a married woman. Rumor has it that the guy is a dead ringer for my father.

Would it be wrong to approach Dad and ask about this potential half-brother, or should I just let sleeping dogs lie? -- OLDER SISTER IN MAINE

DEAR OLDER SISTER: I see no reason why you shouldn't tell your father what you heard and ask if it's true. Not all rumors are true -- and he may be as surprised as you to hear the news if his married girlfriend didn't tell him she had conceived his child.

DEAR ABBY: How do you refer to someone who is in your family through marriage, but is not your in-law? If I'm talking about "my son's wife's mother," is there a quicker way to say it? -- MAGGIE IN NEW YORK CITY

DEAR MAGGIE: Definitely! Refer to her as "my daughter-in-law's mother."