My DD is 4 1/2 and still wears a nappy to bed. She is wet nearly every night. We have started a chart system and that went well for 3 days but then back to wetting. The Herald Sun newspaper recently ran an article on it and they suggested a new product called Slumberdry, which is an absorbent pad which can be washed and put in the dryer if it gets wet. Its about $40. They said that kids find it hard to stop wetting the bed when they are in nappies. I'm going to get one and try it, I'll let you know how it goes, hopefully good news! Good luck.