DEAR ABBY: My youngest daughter, “Lizzy,” the sweetest and most conscientious of my children, has been cut off yet again by her mother, “Ruth.” Ruth pressured Lizzy to graduate from high school a year early because she couldn’t date with a child still at home. (Her words.) After graduation, Lizzy was shipped off to another state for college, then abandoned to find her own funding for continued education.

Lizzy feels unwanted by her mother and desperately wants to know why. The truth is, Ruth didn’t want that pregnancy in the first place and has held it against Lizzy. The deeper truth is I wanted another child and deliberately got Ruth pregnant. I never told anyone, even after Ruth divorced me several years later. As far as I know, she has always accepted it as accidental.

What I did was wrong, yet I can’t imagine a world without my daughter in it. Lizzy is the only one of my children who has become close to me since the divorce. The others all believe their mother’s lies about me — that I cheated on her, which is the opposite of what really happened.

Should I share the truth about her birth with my daughter? I’m not sure because I have always believed it is a major mistake to admit to a child of any age that their pregnancy was a surprise, let alone that it was unwanted. Two of my siblings weren’t planned, and one of them has become a bitter and distant adult. I want to help my daughter understand and accept her mother’s insane actions and get on with her own life. What should I do?

GUILT-RIDDEN DAD

DEAR GUILT- RIDDEN: Lizzy already has a pretty good idea that she wasn’t wanted, and I wouldn’t be surprised if her mother hasn’t told her she was a “surprise” baby. Do not try to expiate your feelings of guilt by telling your daughter what you have told me. That is a discussion you should have with your confessor, not your child.

It may take a therapist to help Lizzy forgive her mother and get on with her life. What you should do is pay for at least half of her therapy and contribute toward her education.

DEAR ABBY: My son was recently diagnosed with bone cancer and is currently receiving treatment. We heard about a fundraiser for pediatric cancer being held in our community. We joined the event and have received many donations from family and friends.

As much as I want to handwrite thank- you cards, between his treatments, my work schedule and my other kids I can’t find the time. Is an email thank you OK? The donations have all been made online.

WANTS TO DO THE RIGHT THING

DEAR WANTS TO DO THE RIGHT THING: I know you are under a lot of pressure right now. However, please refrain from expressing your gratitude by email. Send short, handwritten, personal notes — a few at a time — to those who gave money, as your schedule permits. It is the proper thing to do, and they will be appreciated.

DEAR ABBY: For decades I have been told I look like my mother. The problem is, my mother is ugly! I no longer respond to the comment, preferring to remain silent and just stare at the person instead.

Abby, please remind people that unless the comparison is to an attractive model, opinions should be kept to oneself.

BEAUTIFUL IN MY OWN WAY, RICHMOND, KY.

DEAR BEAUTIFUL IN YOUR OWN WAY: I’ ll remind them, but it’s possible that you’re overly sensitive. The person could be referring to a family resemblance, your coloring or a mannerism. A diplomatic response would be, “Thank you. Isn’t she a dear?”

Write Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.