@greyeyedwonder you would be better posting this on the step parenting forum as you will get very different answers + responses from SM’s who have been in the same position.
I have 2 DSC (boy 16, girl 19). My now DH left his EW as he wasn’t happy (and no I wasn’t the OW and no - he didn’t leave her for someone else). Despite what a few people think on this thread, people can leave relationships because they aren’t happy or don’t have someone else lined up.
His EW told him that if he left her he wouldn’t see the kids again. She tried to see this through but he took her to court for contact and spent years taking her back due to her breaching the order / stopping contact. She used the kids as weapons to punish him.
13 years later she’s still vitriolic and has spent the last 13 years alienating the kids and dropping poison in their ears about their dad and anyone associated with him. The police, CAFCASS & SS have all been involved over the years (as there were alienating behaviours).
The younger boy has been less affected (we think due to some counselling he had ordered through SS). We have a good relationship.
The older girl (who can see no wrong in her mum and who refused to have the counselling) has been very different. I’m only referred to by her mum or the SD as ‘she / her’. For years I was ignored, given monosyllabic answers, she was rude to me and not looked at. Every time my now DH addressed it she told him ‘I don’t know’ or ‘nothings wrong’. We have / had absolutely no relationship (I’ve known her for 10 years).
It really started to affect my MH - being ignored in your own home, being spoken to so rudely and someone being so unpleasant to you eventually wears you down.
For my own sanity I started to adopt the NACHO SP method (look it up). Not your kid, not your problem, disassociate yourself.
His SD is now 19 & has completely cut her dad (me, her paternal grandparents and anyone associated with her dad) out of her life. I had hoped that once she was at university, matured and got out of her mothers claws that it would change, but it hasn’t.
TBH - the relief on my part is immense. I really tried to have a relationship with her but she wasn’t interested. It’s very sad (and yes, I am sad) but it was so stressful putting up with her horrible behaviour. The girl has a loyalty bind to her mum and I can’t see it ever changing.
In your case - your OH needs to be addressing the rude, poor behaviour (just because she’s from a broken home it doesn’t give you a pass to treat another human being like shit).
I would also look up the NACHO method of SP - it could save your sanity.
Good luck 🤞