DEAR ABBY: I have been widowed for seven years. My husband served in the Air Force in Saigon during the conflict in Vietnam. We met and married shortly after he returned from his hitch overseas. We had two daughters together.

Recently, my older daughter was notified through social media that she has a half-sister, "Leiba," from a woman her father knew in Vietnam. They agreed to meet this weekend for lunch at a local restaurant.

My daughter asked if I would accompany her to this meeting. I told her that while I had no qualms about finding out he had a child with another woman, I didn't see any point in my being there to meet her. There is no connection there for me, and I would feel uncomfortable in the situation. Am I wrong for not going with my daughters to this luncheon?

- Unrelated in South Carolina

DEAR UNRELATED: Although you feel no connection to your late husband's love child, Leiba is related to your daughters. If they choose to develop a relationship with their half-sister, you cannot ignore her existence forever. Your daughters may be asking for your support. If you decide to go, do it for them.

DEAR ABBY: I have a daughter, "Imogen," who has been married to her narcissistic and controlling wife, "Brianna," for 20 years. Imogen's relationships with me, my husband and her sister have been entirely dictated by Brianna. We're not allowed in their house, her calls are made from the car, I have not been invited to birthday parties for their two boys, and I'm told not to attend my grandson's swimming competitions if Brianna is in the building.

Two attempts at divorce by Imogen were unsuccessful, the last one having been a month ago. Imogen appears to be willing to accept verbal abuse and non-negotiable demands from her wife, interpreting the control as caring behavior. This cultlike existence has resulted in resentment and disappointment. I'm at a loss as to how to help my daughter extricate herself from a life of dysfunction and dependency. Any advice would be appreciated.

- Worried mom

DEAR MOM: Your daughter will not leave Brianna until she's ready, but that doesn't mean you should give up. Avoid criticizing Brianna directly but continue to ask Imogen how Brianna's controlling actions make her feel. Getting her to think along those lines may lead her in the right direction. Above all, make sure she knows about the National Domestic Violence Hotline at 1-800-799-7233, and remind her that controlling behavior is a form of violence.

Contact Dear Abby at DearAbby.com.