It's a beautiful thing when your child sleeps 12 hours in a stretch... and very healthy. I would just work on moving her schedule so she's in bed by 8:00 pm and up at 8:00 am. She really should regulate her body to night & day.You can also try putting her down for a nap mid-day for 2 hours of so.My son sleeps from 8:00 pm to 8:30 am... and takes a nap between 1:00 ~ 3:00 pm. He's 20 months old.