what is her level of understanding like?
when dd1 was going thrugh a ropey phase, we introduced an alarm clock wiht some success.
we used one which lights up a picture of a rabbit in bed vs a rabbit skiping along htorugh sunlight depending on day/night times set.
we told her that hse had to stay in her room when the rabbit was asleep, and set the clock for 5 mins after her (then) usual wake up time.
slowly, slowly, we pushed the alarm time back, by 5 mins at a time.
if dd1 managed ot stay in her room unitl the rabbit woke up, she got a choc button after breakfast (was initially as I went in to her for immediacy, and then I "forgot" one day, so we had it downstairs after getting dressed, etc).
it worked, after a fashion...