When you put her to bed at nite read her a story and sit with her until she falls asleep. I know this may sound crazy but I had to do it with my youngest son. I would read him a story and than rub his back until he fell asleep each nite after a while it took less and less time. Sometimes children are just afraid to be alone. When she comes and gets in bed with you just get up and put her back in her bed. You have to be consistant.