Daughter with cp waking about 3 times a night

Hi any advice would be appreciated.
My daughter is 5 & a twin she had athetoid dystonic quad cp, she is very high muscle tone. She goes off to sleep about 1930 earlier if she is exhausted, she has story & cuddles before she goes to her own bed to fall asleep. She is waking about 3 times a night & then tends to wake up between 0330 & 0430 she has tried melatonin which didn't work she is on a drug tetra benzine which was working for a bit but not working even after a increase in dosage. I'm all out of ideas any help would be great. Many thanks
Sally x x x