DEAR ABBY: I caught my husband talking on the phone to another woman. I heard him say, “Get some sleep, sweetheart,” and “Thank you for being my companion.” When I called him on it, he claimed nothing was happening and he had used the wrong words.

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.

Whatever caused the rift with your sister, it is clearly more serious than “distancing.” If you put your thoughts and feelings in a letter to her, it will let her know that you love her, are concerned about her diagnosis and ready to do whatever she will allow you to do to help.