Something in her past is possible. She's suspected that something may have happened to her as a child that she has blocked out, but has not desire at all to try and find out about that.
From what i can tell i think her parents have a SSM but it doesn't seem to be a problem for them. Perhaps one of the reasons she doesn't understand how it is such a problem for me.
Her parents are workaholic perfectionsists who were very controlling of her as a child.