Hi - I have a 20-something daughter that is much like yours seems to be.
Mine has not spoken to me for about a year now because she must follow the same rules as her brothers did. - Be respectful, be responsible, be part of the family. - She consistently was rude to my wife, did not attend college classes properly and was late or did not show up at family functions. I made her move out. I paid the deposit on an appartment and the first months rent. From then on, she has been on her own. If she fails, she fails - but she is not in our face everyday anymore.

It was the hardest thing I ever did and I miss her very much. That is, I miss my daughter....not the little "pot" she has become. I had to remember that my other kids needed me too. And, they have turned out ok. All I can do is pray that someday she will too. But, I refuse to put up with her "you know what". And, it is not fair to the other kids if we let her off the hook.

I think you know what to do. The next step is doing it.

Good luck:-)