My daughter is 7 weeks old and usually drinks anywhere from 2-4 oz every 2-3 hours never more. Well at night she wakes up very often and only drinks one oz then falls asleep. We try to wake her a bit, change her diaper. Tickle her feet and nothing works she is in deep sleep and wakes up like 30 minutes to and hour later. I am completely exhausted is there anything i can do to either keep her awake enough to drink the whole bottle or can it just be happening out of habit?