What about taking her to rehab, dropping her off, telling her if she leaves the police have a warrant for her and she will be in jail by night.
Call the police while your at the rehab with her and tell them she's in rehab?
I think the police would rather her be in rehab than jail?? If they let her stay
you could ask them to come to the rehab and have a chat with her there also..
One of the reasons I got clean the first time was from a cop and a chat he had with me, lol. He was very cool........
Just a thought..