Would she understand a little star chart? Every time she stays in her bed she gets one and once she gets 5 she gets a little treat/toy? We find using one with ours (although they are a fair bit older) only takes 1-2 charts and they get out of the habit of mucking around. Also if she is getting a new bed, new sheets she can choose might help as well so she has something she is excited about? Good luck!