For the past several weeks LO (23 months) has been consistently waking 1-2 hours earlier than she used to. I know it's earlier than she should wake too, because she's ready for naptime by 11AM when she wakes early, whereas she naps at 1 when she sleeps to a normal time. Also, she only does this during the week, not weekends. Any tips? We've done earlier and later bedtimes, nap length doesn't make a difference, and just leaving her doesn't do anything.