That sounds so difficult. I think I would have to address the issue with her and if she doesn't get it move on. I understand your pain and for a t to be so insensitive is quite amazing. I'm afraid I have no insights into why she does it, but others might. When people did similar things to me I just decided they were really insensitive and ignorant. It was too painful for me to easily forgive them. Saying that I do think it is worth a go discussing it with her.