Hi everyone, my little girl is 21 weeks old and is on 3 1/2 hour EASY (she can't quite stay awake for 2 hours). At her nap times she wakes at the 45 minute mark and cries (i'd actually call it whinging) and will then fall back asleep. Why does she do this, how can i teach her to get into the next sleep cycle without the crying? Also at what age does is the sleep cycle longer than 45 minutes?