Thanks everyone. Maybe she is getting enough then. It might just be that school is wiping her out. Apparently she is an angel at school (thankfully!) and absolutely loves it, but when she comes home she's horrid! I have started giving her a bath on her own after she has her afternoon snack, to help her calm down and relax a bit before she interacts with her brothers, otherwise she's saying and doing horrible things to them and making them cry!

I can't make her sleep (God know's I have tried through the years!) and hopefully she will regulate herself to catch up and get enough.