there is a sleep regression at 18 months. but do rmb that follow the 3 hourly sleep schedule don't over stimulate them. try using a carrier to calm them down and make them sleep
she will usually have a short nap between 4-6 plus for an hour and 30 minutes..
oh not that's not very good. how's her sleeping routine like?
after which, she will continue to play until past 3am