Does she wake on her own or are you waking her? I've know n some kids that wake as bears and what has worked is slowllllyyyy waking them. So start by opening their door a good half hour before you want them up. Then turn on the light. Then make some noise. Just slowly bring them out of sleep so it's not a sudden wake up.

For kids (people) who just are slow-wakers it is really, really hard to wake and be happy with a rowdy bunch of kids around you.