Have you got a routine before going to bed and maybe while she is first in bed.

The same thing happened with my nephew and the only way we coudl cure it was to have quite a drawn out going to bed routine which involved much prebed faffing about but also a story and then counting the glow in the dark stars on the ceiling (which can only be done when the light is off)

There was also a deal that if he woke up first he had to count the stars then he had to practice his wistling (which he can't do gratefully) before he got up.