From what you have said here, I would just suggest she ask you, "Are you sure you have finished with this topic?" when you change to a new one. You may just unconsciously be 'changing the subject' when things make you anxious. I know I will sometimes find myself in the kitchen, looking in the refrigerator wondering how I got there and go back over what I was doing/thinking and find I might have been reading or something and had a thought/read something that made me anxious.