It sounds like subconsciously you are afraid of overlying and being late for school and letting your daughter down. Therefore you are waking up so as to ensure you wont be late. Just before you sleep tonight and the very last thing you think of tell yourself you're going to have a great sleep, you deserve rest and nothing, nothing is going to wake until the alarm clock goes off. "I'm not waking up until I hear the alarm" embed this into your subconscience. It's easy to mapipulate sleep paterns with techniques like this and a little practice.