She may just wake up when you're asleep, my hamster has got into a bit of a routine now where he wakes up and knows its playtime before i go to sleep around 11pm, whereas when I first got him and he wasn't use to my own routine, he would wake up around 1-2am and still be awake when I woke up around 8am, and then sleep the rest of the day. I doubt she's over sleeping, just awake when you're not!
