My 18 month old keeps waking at 4:30 am. She used to sleep until 6 am, when she would wake to nurse, but now nothing makes her happy until I bring her to my wife to nurse. My wife can't sleep while my daughter nurses, so she won't let me bring my daughter in until 5 am and then my wife is usually up until 6 am, at which point she gets up and goes to work. It's wearing both of us out. I've tried walking my daughter, rocking her, bringing her water or milk (she refuses both) and she just stays awake until I take her to my wife. This was true even when I tried to make it until 6 am. We just can't figure out what's behind this sudden and annoying habit but it needs to stop.