I am asking for my daughter and she wants to turn herself in today what should she expected?

She has reason to be afraid. There is no doubt a warrant out for her arrest, and that is what will happen when she turns herself in. But, the good news is that it is so much better that she turns herself in than she be arrested on the warrant. She will be taken to the judge in short order and she/he will decide what to do now. She could be sent back to rehab, or she could end up in jail or prison, depending on a number of factors. But again, it is better that she decided to face the music despite her fears.

If she is supposed to be serving a sentence, she will have to serve the remainder of her sentence. If she is turning herself in on a new charge then she will be given the opportunity to post a bond. If the court ordered rehab was a condition of her bond, then her original bond will be revoked. If the rehab was in lieu of a jail sentence, then she may be charged with escape. More details are needed for a more specific answer.

She will be placed in jail until she can have a bail hearing. Given her previous actions, bail may be high.