Me and my ex best friend were friends for about 20 years but throughout that time she was very controlling and would use every situation as an excuse to embarrass me in front of our peers and even my partners. Looking back she also bullied me throughout school and turned all my friends against me for no reason. About 3 years ago I decided the friendship was doing me no good so cut all ties, which she was understandably upset about, but I just needed to do it for my own mental health.
However, every couple of months for the past 3 years she'll send me messages saying she saw something that reminded her of me or a post on Facebook we were tagged in together from years ago when we were very close. They're harmless messages but they make me feel guilty and every time I see her name in my messages I feel like that bullied 13 year old all over again.
How would you handle this situation? I've already said to her 2-3 times that I don't want to rekindle our friendship but wish her well, what else can I do? I don't want to block her because I know it'll hurt her feelings and cause animosity when I don't actively dislike her but her constantly reappearing every few months stresses me out.