My 4 year old is autistic and has little language understanding. He generally sleeps ok but wakens at least 1-2 times a night. My 3 yr old is a bloody disaster. They both take a cup of watery juice to bed but the little one wakens 5-7 times a night. That's an average night. They share a room and generally he's easily settled ie go in change his nappy and top up his cup. I know this is terrible but I haven't a clue how to stop it. Please help.