@anon234355
Have you told your parents about it yet?
It's very sad isn't it. So many of these type of men were abusive before marriage and kids, yet women still go ahead with marriage.
I couldn't forgive my Dsis (or I'd really) struggle if she couldn't even respond to me, but thankfully she would never do that.
I know because in one incident my BIL was out of line (nothing near as bad as stalking me) and I was very clear that I wouldn't be going to their house again. I would have seen her elsewhere.
She had words with him and he apologised immediately.
Has she got low confidence? Does she somehow feel lucky to have him because he's good looking or something?