hi Frida24,
Well, I don't have any advice or insight, but I wanted to write you a note and say "I relate." My step daughter was 19 when I met her Dad. She's 26 now, married with 2 kids under the age of 3.
She was living with her Dad, her parents had just split, when I met her Dad and thus her. There were definetly some signs early on. She moved in with her Boyfriend (now husband) and his parents because "I was a bad influence on her dad." They are super religious, I won't say it's a cult, but it's one of the stricter religions (no surprise, as she pulls this moral superiority thing on everyone). She does not drink, except with her sister when it suits her (most of the time spent with us has been bad mouthing the sister). She has just a handful of friends, they are mostly her husband's as far as I can tell. The moving out - this was done with high drama, one day when my husband was a work, she left and all her things were suddenly gone. She sent some texts to let him know he screwed up. I think moral reasons were brought up, like I was sleeping over. I was also going to make her Dad go into complete mental melt down, as she was his "best friend" and knew I wasn't good for him. He did make the mistake of getting baptized in her church...(another story, but you can see the enmeshment before I came along).
It's hard to write this, it sounds like I'm making it up.
Fast forward 7 years. She disowned her Dad last year because he wouldn't divorce me. We are also not allowed to see the granddaughters. Did she not speak to us this entire time? No, it was off and on for the past 7 years. We did break up once for a week because I texted her (this was before I married her Dad) and she took offense. Dad took her side.
now it's kind of comical
We have moved on and are no longer a hostage to her tirades. It did take marriage counseling and a lot of tears, sweat and anguish to get to this point. It helps my Mom is BPD, so when our marriage counselor suggested it, it was like an Ah-ha moment.
good luck, I'm hear to listen
b