We have just moved my 5 month old into her own room and into her cot. Having previously slept through until 6.30/7am, she is now waking at 5.30/5.45 and is WIDE awake and refuses to go back to sleep. Her nursery is as dark as I can make it... any suggestions/advice on why she's waking early & what I can do to get her to sleep a little longer?