I haven’t had that specific problem, but generally speaking, a “time to wake” alarm clock has been helpful. It lights up a certain way when it’s an appropriate time for them to actually get up. So we taught our daughter – don’t come out of your room until the clock shows it’s wake up time. If she wakes up earlier she knows the light isn’t on so it’s still sleep time. They are on Amazon and a little spendy but so worth it!