Super nanny all the way!
What is she doing when you say she is up to 10pm? My attitude has always been 'if you're in bed & quite it's good enough for me'. I've even turned a blind eye to tea-parties in the dark :-/ but take one step out of your door way & I'll put you back to bed.
Have you seen super nanny? Basically it's a consistent bedtime routine, really nice & calming, have a chat/read a book & kiss good night. If they get up you don't speak to them, just carry them back to bed & leave (no talking, no kiss, etc) & repeat.
First time we did it I think dd got up 16 times, 2nd night a handful of times & third night she stayed.