DD (just 3) has been waking early for several months too and like you, no daytime naps, blackout blinds etc. had no effect. However we have come to the conclusion over the past week or so that her maximum sleep requirement is 10 hours a night. She used to go to bed at 7.15ish. We knocked this on to 8pm and it didn't really have much effect - still waking anytime between 5 and 6.30. The odd late night didn't result in sleeping on any later in the morning.
Unusually she fell asleep on the way home from swimming last week and I didn't wake her on arriving home. She slept for almost 1.5 hours (this is a child who hasn't slept during the day since around a year old!) As a result she didn't get to sleep until around 9.30 that night but then went on to sleep until 7.30. Since then we've been putting her to bed at 9. She is asleep almost immediately and sleeps until at least 7 on most days. I know it isn't ideal but I'm happy to run with it during the holidays at least - I'd much rather have her up later (and she doesn't seem that bothered) than awake at the crack of dawn. She starts back at pre-school in a few weeks and will be back for an extra morning. I hope that helps too!!
Thanks mejon, I also think that DD needs less sleep than other children and that I will have to put up wither either late nights or early mornings. When we were on holiday she slept from 6.45 until 6.45 so I think the answer might be to completely wear her out but I am 12weeks pg and its exhuasting.
Lets hope pre-school means then need a bit more sleep!
I had this with ds (now 2.5 years). In the last couple of months we got one of those clocks with a bunny face on them, and told him that until bunny wakes (at 6), he has to stay in his bedroom, playing quietly. Once bunny is awake, he can come and see mummy and daddy. Mostly it seems to work, and he'll play (not necessarily quietly) until 6. However, sometimes he'll get impatient and will change the clock himself to wake bunny up, and then will triumphantly stride into our room saying 'mummy wake up, bunny's awake now' at 5.30.