For 23, yes 23, years I have tried to have a relationship with my SD and have met with nothing other than passive aggression or downright ignorance in return.
She will speak to me if I speak to her first, but only one word answers or at best short sentences.
I have tried so hard and got absolutely nowhere. DH has spoken to her, but it has madeno difference. At the same time, for what It's worth, my DC have a reasonable adult relationship with my DH of 20 years.
Today takes the biscuit. It is her older DC's first day at school. She has sent DH a photo, taken from above so you cannot see his face but only the top of his head, and told DH he cannot show this to anyone else because DC has the school logo on his sweatshirt.
I actually feel sorry for her. She had a rotten childhood being a carer for her mentally ill mother, while her father was living it up on the other side of the world, and she is now in an abusive relationship, but even so, I think I'm done.