DD is now 4 and a half months old and in the past week she's been much more whigey and hard to settle than usual. How much sleep should she typically have in the day+night? The last couple of days she's slept loads in the day but been impossible to settle at night, and today she's had hardly any day sleep, just a couple of teeny naps and she went straight off for the night. So need advice about how much to let her sleep in the day, in case she won't sleep at night.