In the meantime, here are some other things to consider. If your daughter is tired during the day and takes a nap after school (or at school), this of course could be the cause of her night-owl behavior. If she takes a long bus ride home, she could also be catching 40 winks then. Ask the bus driver. Also consider what she's eating. She may be taking in significant amounts of caffeine in candy, soft drinks (even the "clear ones"), or coffee-flavored foods (coffee ice cream, for example). She might have an allergy to certain foods or food additives that make if hard for her to relax and fall asleep at night.
Exercise can help to tire her out, but if she exercises vigorously just before bedtime, it can keep her up. Do you have rituals around bedtime? Warm bath, warm milk, or a calming time in a dim room? How about a story time when you read to her? Your little girl will be more likely to become sleepy if she's not reading or looking at pictures. Have her close her eyes and "imagine" the story. How about soft, classical music with the lights off?
Have you considered meditation? Suggest that your daughter softly or silently say some special word over and over again until she drifts off. I used to have my daughter close her eyes and "stare at the spot on her forehead," which I "put there" by touching it with my finger. (She still uses this technique as a young adult!) You can also have your daughter lie on her back and hold her hand up in the air and stare at her fingertip. Do this as a challenge. Ask her how long she thinks she can keep her arm up. Chances are that won't last too long -- you'll be hearing Zzz's before you know it. If you want to pursue this approach (or biofeedback, which can help your daughter put herself into a state of mind that will allow sleep to come), you can take your daughter to a psychologist who teaches kids how to relax themselves by using relaxation or self-hypnosis. (Call your state Psychology Association for a referral.)
Finally, you'll want to make sure that your daughter's "internal clock" is working well. Her sleep cycle could be disturbed by bright lights coming in the window, or some other reason. If this problem doesn't get better, you might want to take her in for a sleep study at a local children's hospital. Good luck and hopefully, good night.