How can I get my daughter to sleep in in the mornings?

My daughter is 20 months and I can't get her to sleep past 6 AM. She goes to sleep at night around 9 and is wide awake in the morning. I would like to get her to where she would sleep to between 7:30 and 8 but I don't want to keep her up longer for it. Is there anything I can feed her that may help? Something to relax her more at bedtime?