I am a terrible sleeper and find that I fall into a deep sleep about 2-3am.
BUT
DD2 is nearly 6 and for the last few weeks her sleep has got gradually worse and worse.
At present we are at a point where she is waking us any time from 4am onwards and crying etc and creating because she wants to get up. She woke at 4am this morning and when we went in after 3 hours of crying and creating she was fast asleep.