Child needs daddy or visa verse?

There is a girl whos 22 years old and was put into a rehab for 2 weeks because she kept threatening suicide. Mom and dad are divorced she lives in her dads apt but dad is remarried and lives nearby. At every visit she promises she is sorry ,she wont commit suicide she was doing it for attention. Now 2 weeks later she is discharged from rehab and back in her apt and dad keeps a close eye on her. Question..Should dad have to move back in with her just because that is what she wants or should he stay at home with his wife and continue to monitor her. The girl comes over to the dads house from time to time but there are other kids living there who are afraid of her addictions and dont like to be around her. She calls him all the time for the silliest things and yes she does get along with the stepmom but cant live with them because she cant be trusted. What would you suggest?