DEAR ABBY: My granddaughter's 13th birthday is approaching. It is special because she will be a teen-ager, an exciting time filled with new experiences and responsibilities. I would like to give her some advice about boys and dating. She is already boy-crazy. However, every time I try to tell her something, she says, "Oh, Grandma, you're so old-fashioned! Things are different now."

What I need is some advice from you, Abby. She reads your column every morning before she goes to school, and she doesn't consider your advice old-fashioned.

Please, Abby, can you help me to help my granddaughter? -- GRACE IN GRAPEVINE, TEXAS

DEAR GRACE: Your granddaughter is right about one thing: Things are different now from when you were her age. Teen-agers today must handle far more complex problems than either of us faced when we were young. Today's teens face pressure to have sex, and risk contracting sexually transmitted diseases if they do become sexually active. There is the temptation of drugs, and they must deal with more violence than we ever did.

We have fewer stay-at-home mothers these days, and without the necessary time to communicate with their parents, young people often pick up what they can from other teens who are equally inexperienced. For that reason, I wrote my booklet, "What Every Teen Should Know," which answers many questions teens have about sex, love, drugs, and how to handle the many pains of growing up.

The booklet has been used at both church and nonsectarian summer camps, and many teachers have suggested that it would be even more helpful if it were given to children ages 10 to 12, because today children mature earlier physically than they did a generation ago.

To order, send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: When I was very young, my brothers molested me. I have tried everything to get over my anger toward them, but I still feel that they "owe" me.

Abby, my marriage failed and I have never had a stable relationship because I feel that every man is lying to me and is out to hurt me. I just can't seem to get past the pain. I would like to put this behind me and forgive them, but I can't. -- MOLESTED IN MILWAUKEE

DEAR MOLESTED: You say you feel that your brothers "owe" you and indicate that you cannot heal because of your anger. They cannot repay your stolen innocence, nor can they undo your trauma. As an adult, only you have the power to heal yourself, with the help of others who have been in your situation and with professional counseling. Counseling and a self-help support group are not options; they're mandatory if you're ever going to put what happened behind you. At that point you may -- or may not -- choose to "forgive."

For the location of a support group in your area, send a long (business-sized), stamped (33 cents), self-addressed envelope to: Survivors of Incest Anonymous Inc., P.O. Box 26870, Baltimore, Md. 21212.

I urge you, and anyone who has been molested, to take that first step toward healing today. Don't delay. Write for information, and ask your doctor to refer you to a counselor.

DEAR ABBY: My husband and I went to Pennsylvania the last week of December and slept in a motel room that we noticed had an unpleasant odor. It was not from smoke. We had requested a smoke-free room and got one. However, I had an allergic reaction to something, and had a difficult night.

The next day I mentioned it to the maid, and she told me there had been a "cute little doggy" in the room the night before. I then told the manager about my allergy to dogs. She did not apologize. She said, "Well, we like our pets ..." Needless to say, we will never frequent that motel chain again.

My husband and I do not hate animals, Abby, but we don't want to eat or sleep with them. Maybe others feel as we do. We know that people who eat and sleep with their dogs would smuggle them into a motel any way they could. The few motels that enforce the "No Pets" rule should be commended.

Thanks for listening, and for printing this. -- ABBY FAN, FAYETTEVILLE, N.C.

DEAR FAN: Your mistake was in not mentioning the fact that you have an allergy to dogs when you requested the smoke-free room. Just as there are smoke-free rooms reserved for guests who suffer from a sensitivity to cigarette smoke, there should be rooms available upon request for those who have pet allergies. Try it next time you and your husband are traveling.

DEAR ABBY: The letter from "Mourning in Texas" prompted me to write. "Mourning" was disappointed about the small number of floral arrangements sent to his late wife's funeral.

You were correct in stating that many people donate money to charity in order that "something good" may come from the sadness of a loved one's death. However, we should all remember that floral arrangements sent to a wake or the home of the grieving are also "something good" -- and useful.

Too often, people hesitate to send flowers thinking they'll be thrown out after the funeral. But what is important is the message of condolence that flowers convey to the grieving family during those extremely difficult few days. Flowers are for the living -- they say, "We loved her, too. She had value to us, and we care that you are grieving."

This is not to say that making a charitable donation isn't worthwhile, but to remind people that sometimes flowers speak volumes.

May I share with you what my husband and I do at such times? When we attend a funeral or a wake, we take a card and a single rose. One week later, we send a "thinking of you" card. A month later, we send a colorful arrangement of flowers to the family of the deceased to let them know they are still in our thoughts and prayers. I cannot tell you how often we are told, "Thank you for thinking of us. It feels as though everyone's world has gone on and no one remembers we are in pain, but you remember."

Abby, it makes us feel wonderful to let someone know they matter. -- FLOWER FANS, LONG ISLAND, N.Y.

DEAR FLOWER FANS: That's a terrific plan of action, and one from which many can learn. Too often, after the funeral and all the offers of "What can I do to help?" -- there is only silence.

To order "How to Write Letters for All Occasions," send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Letter Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: If this letter can save one person's life, it will be well worth it.

I was experiencing headaches for quite a long time, and my husband was sleeping in his chair quite a bit of the time. The day of our grandson's birthday last November, I could hardly think because my head hurt so bad. In spite of it, I drove to the party and started to feel better. I told our son about my headache, and he said he would check our furnace for us.

Because our furnace was quite new, we never gave it much thought. The automatic damper was shut, and the furnace was emitting carbon monoxide fumes!

Our beautiful kitty, Yvette, had died some time before, and we never knew why. However, she had slept in the furnace room.

I always opened the window at night, and we have a large home, so this is probably what saved us.

I hope you'll alert your readers to have their furnaces checked -- even if they're new. I cannot stress enough the importance of this. -- PATRICIA IN PORTLAND, ORE.

DEAR PATRICIA: Your letter gives new meaning to the phrase "wake up and smell the coffee." Carbon monoxide is a deadly killer, and every year the news reports deaths because of improperly vented heaters. Having one's furnace checked in the fall, before the cold weather hits, is a wise precaution. Since the winter season is now upon us, I hope my readers will heed this warning immediately.

DEAR ABBY: I'm a 37-year-old mother of three. Until recently, I had a wonderful relationship with my mother. She's a beautiful lady who adopted me when I was 5. Mother is a teacher, author and political activist.

However, as she begins her 82nd year, our relationship has taken a nosedive. For years, she has been strong-willed about discussing her political views at every gathering and conversation. Guests have literally run out of the house after being badgered by her, and quake at the thought of visiting us. I finally gathered enough courage to tell Mom that her outspokenness was embarrassing me and my friends.

My reprimand worked for about a year. However, during the past three months she has been avoiding me. She refused to attend the family holiday parties and asked to see my children without me. She flatly states that my demand that she stop talking politics all the time is "unfair."

Her behavior is startling to me, and I'm unsure how to handle it. I hope you'll have some insight on how I can mend this fence. -- PUZZLED IN NORTHERN CALIFORNIA

DEAR PUZZLED: Given her professional background and her age, I'm sure your mother feels that the world wants her opinions. She's punishing you for not being receptive to her ideas. You aren't going to succeed in "muzzling" your mother, so apologize. Be grateful that she cares enough to have a viewpoint -- and tease her about it if she becomes a bore.

Everybody has a problem. What's yours? Get it off your chest by writing to Dear Abby, P.O. Box 69440, Los Angeles, Calif. 90069. For a personal reply, please enclose a stamped, self-addressed envelope.