My 4 mth old dd is a very light sleeper and cannot sleep for more than 45 minutes at a time during the day, however tired she is. At night she settles well at 7 after a feed, sleeps until 10.30 where she is fed again. She then wakes at 3.40 am wanting to start the day and cannot put herself back to sleep. She is not hungry (she can be up for hours the next morning without wanting a feed) but if left will start crying after about 45 minutes. It usually takes 1 to 1 1/2 hours to settle her back to sleep- I have to hold her arms in the swaddle and keep putting the dummy back in. She then sleeps for exactly 45 minutes and wakes again and by this time there is no real point in settling her back again! We have tried putting bedtime later but, as she doesn't sleep much during the day, she is exhausted by 7. Is there anything I can do about this or do I just have to accept being awake from 3.40 every morning....?