I was getting to know a woman and we went bicycle camping for a weekend. An issue came up and she would just not let it go. I felt close kinship with her ex-husband who I have never met. I survived the weekend and never called her again.
I feel sorry for you. She's a first rate nag and her bringing it up when there is company is an indication of her nagishness. (if that's a word) She is pathetic and refuses to take responsibility for herself. I bet this is just one of a dozen issues she has.