Olive - I know how hard it has been with DD2's sleep (or lack of). We have only just got DD2 to stop feeding overnight. She doesn't need it and she was waking just for comfort. I had to take a harder line with her as I am going back to work next week and I can't be up 3 times a night but honestly I don't think formula will make a difference as it does seem like she is waking more for comfort than hunger.