DEAR AMY: My 24-year-old daughter graduated from college two years ago and moved back in with me last year. I realize my daughter is an adult, but we have had some issues about her smoking pot, which I do not allow in my home.
My daughter works part time and has her own money. Recently, she has been going upstairs and spending a great deal of time with a 60-year-old female in-law, who lives in the same building as us. One evening she came back from a visit and she was so high that her eyes were barely open and her speech was impaired. I confronted her and she confirmed that they smoke pot together.
I think a 60-year-old woman should not be smoking pot with my 24-year-old daughter. This woman is a bad influence on her.
Should I confront this in-law and tell her I consider her immature to be smoking pot with a 24-year-old? She knows I have been concerned about my daughter's use and her recent behavior changes, including her laziness.
I don't care what this other person does, but I do care that she is encouraging my daughter to use drugs that have kept her from passing a urine test for a permanent job. — Concerned Parent
DEAR CONCERNED: You want to confront the wrong person about your daughter's drug use.
Your daughter will find someone to smoke pot with as long as she is using pot, whether it is a family member, friend, or co-worker out by the Dumpster. Her behavior is the immediate problem in your household.
I shared your letter with Charles Rubin, author of "Don't Let Your Kids Kill You: A Guide for Parents of Drug and Alcohol Addicted Children."
Rubin says, "You must take a firmer line and tell her to get a full-time job or work full-time hours within a specific time frame. Tell her, 'If you're smoking you obviously won't be able to get that job and I won't be able to offer you housing any longer.' Give her a deadline and calmly stick to it.
"You are important. Your daughter needs to see that you stand up for yourself and your values, no matter what. In addition to preserving your own self and health, you have the opportunity to influence her by your example."
She may stalk out and move in with the pothead upstairs. Keep talking to her and keep a firm line on sobriety. That's how you practice both sides of the whole "tough love" concept.
DEAR AMY: I would like to know how to handle a situation in these modern times. What do I do to keep overweight or obese houseguests from sitting on my antique furniture?
I know this is a sensitive subject, but you can't expect people to go out and buy new "plus-size" furniture to accommodate the growing poundage of our society.
How can this be handled without offending or hurting friends and family? — Need Help
DEAR NEED: If you have antique or fragile furniture that cannot safely seat a regular guest of your household, then yes -- you should definitely acquire something "plus-size" that can accommodate your guest comfortably.
Otherwise, would you have a guest stand in your home, wheezing, while you urge him to diet?
You should always steer your guest toward the most comfortable (and secure) spot by saying, "That old chair is a little fragile. Why don't you sit on this one while we visit?"
DEAR AMY: Responding to "Angry," whose mother-in-law is adamant that her unborn baby must bear her family's name, I strongly suggest that the mom-to-be realize her problem isn't with her mother-in-law but with her husband, who won't stand up to his mother when she oversteps boundaries.
I had a similar problem, which almost cost me my marriage until, in counseling, my husband realized his mother was his problem to deal with, not mine.
Once he took care of business, our marriage became more unified and loving. — Been There
DEAR BEEN THERE: I agree that the burden for creating boundaries falls mainly to the offspring.
Send questions via e-mail to email@example.com  or by mail to Ask Amy, Chicago Tribune, TT500, 435 N. Michigan Ave., Chicago, IL 60611. Amy Dickinson's memoir, The Mighty Queens of Freeville: A Mother, a Daughter and the Town that Raised Them (Hyperion), is available in bookstores.