Hi,
How is your daughter? "De ja vu" is pretty common during this age. If over-the-counter pain medications do not help with her headaches and if numbness in her legs persist, have her checked by her doctor for proper management. Complete physical examination will help determine the underlying cause.
Take care and do keep us posted.
I have to say 12 years old, is at that age to start developing. The headaches could in fact be from hormonal change. As far as numbness in legs and arms...maybe it is just migraines and possible pinched nerve. I would take her to see a pain managment doc or even better a chropractor. They do magical stuff!!! I was having headaches all the time when i was in my teens, along with pain in my fingers and they helped me out with that. As far as the dreams...dont know..kids have good imagnations.