DEAR ABBY: My sister “Maddy” and I were best friends. She was a great sister to all of us growing up. She was a successful career woman and helped many in our family.

She met a British guy online, got married and moved to the U.K. When they visited, we noticed Maddy had become a different person. She had lost her decisive personality and had become a docile, “can’t go anywhere without my husband” individual. She couldn’t even spend her own pension unless her husband approved it.

When we tried to talk to Maddy about it, she became defensive. I saw abuse but couldn’t do anything. This has created a rift between us. I am sad because I have lost my sister and best friend. They have now retired and returned to the U.S., and my siblings barely tolerate her husband when he’s around. Any advice? — DIFFERENT IN THE SOUTH

DEAR DIFFERENT: Just this: One of the first things an abuser does is try to isolate his (or her) partner. Maddy’s husband may have succeeded in not only isolating her but also dominating her.

If you are right about her having been abused, every sibling she will listen to should impress upon her how much they love her and that they will ALWAYS BE THERE FOR HER. If you are still in contact with her, do the same. (And keep the National Domestic Violence Hotline contact information — thehotline.org; 800-799-7233 — close at hand in case you need it.)

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Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Contact Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.