my dd (16months) has always woken quite early - 6ish, but now she's creeping forward to as early as 4.45am
this is too early 
and she is crabby and horrid as a result. I try to breastfeed her back to sleep with us but she starts kicking about and wanting to run round the room and play with our shoes
I'm quite happy to leave the little brat in her cot to cry (in a controlled and loving manner obv) but wondered if anyone had had any success with this or other ways.
she doesn't wake in the night otherwise
as to whether it's the morning light, she has blackout blinds and to be honest sometimes she wakes before dawn so it's still BLEEDING DARK

please help