Oh dear. This happened to a friend of mine. She moved, with her husband, about 100 miles to be near their daughter and adult grandchildren. Her husband died with six weeks of the move and her family were mainly occupied with work and their social lives. She came home and rejoined all her groups, but it will be a long time until she recovers from the whole episode, if ever.
Your friend will just have to be honest with her children. Hopefully they will understand and wish her well.