Ella was up last night about 1am, and eventually the only way we could get her back to sleep was Neil took the spare duvet and pillows and slept on the floor in the hall outside her room, she fell asleep about 3am and was back up at 6
But thinking she not well at the moment so that may have been a cause with her.
I have noticed the nights she wakes up, she wants us to take the canopy off her bed - she has the princes carriage with the canopy over the top. It seems to freak her out every so often, but then wants it back a few nights later
Good luck, hopefully you find some answers soon