I lived with a Daisy type once. Actually, she was more Single White Female without the murderous tendencies.
Discuss the situation with the other roomies. In my experience, it doesn't get better, only worse. Don't let her move in or you will be subjected to this type of behavior for the length of the lease. You know how you feel now after barely two weeks. Imagine how you will feel in a few months. There is no reasoning with a person like "Daisy" so I wouldn't even try if I were you. I went through it myself, and I wish that I had moved out or had thrown her out of our home.
As for the lease, find a new person to take over her room. Your landlord can't force you to live with someone who steals and is a source of other problems. She will be a bad roommate as well as a bad tennant. Good luck!