Difficult young adult step daughter

[Hpsauce21]

Hi! I would really appreciate any advice with this! I've been in a relationship with someone for over a year who has a mid twenties daughter. Her parents separated 6 years ago but this is his first serious relationship. I expected some difficult times perhaps but I'm finding things are getting worse. She is very condescending to me, questions when her dad treats me, turned up for my birthday meal over an hour late and never offers to help when she comes over. I helped her get a job last week and this week she stayed overnight, came back from a night out at 2am, threw up everywhere and so was late for her new job and hungover. Her dad wasn't at home that night. Every time we seem to be getting on and I relax she then does something worse. Help!

Is she always like this with everyone?
Sounds more like a slightly out of control, over indulged child.

All I can say is try to keep yourself separate from her, don't do her favours setting up jobs etc. Do you live with her dad? Does she live with him or stay there regularly?
If she calls it home too there isn't much you can do, if she's sick all over or coming in late then she is being disrespectful and it's worth mentioning it to your DP, but be prepared to be the one in the wrong. Of course don't be trying to clean up her messes, either figuratively or literally.

I'm not sure why she's staying if her Dad's not home?

She's mid twenties, so should have her own life, and just visiting yours to be a guest. Perhaps don't expect her to help out when she comes over, but don't expect her to behave like a child either. She's a grown up, she'll have a partner at some point I imagine who she'll want both of you to accept. Maybe lay off on the birthday invites, don't expect too much.

She is a bit of a princess though I could never say this to her dad - a lot of designer clothes and going to expensive restaurants while asking her dad to pay her rent. The invites will have to be minimised for a while until I feel I'm getting some more respect. It's made worse by the fact I left an emotionally abusive relationship where I was totally disrespected - not sure I can face this all over again.

Be warned this girl is using Her DF as a meal ticket and a place to doss! She's in her 20's and should be fending for herself, so I'd back right off!
If you are living with your DP, then she'll probably continue to treat the place as her own, just to let you know she can! To be honest, in these circumstances I don't think I would have moved in, you'd be better keeping your own place for a while, just so you don't have to be involved in her Daddies Princess routine, she'll settle with someone eventually, and her daddy won't see her for dust!

Thanks for all the advice - she was actually staying over at my place because it was nearer than her dads. I have kept my own place and her dad stays over a few nights a week.