Its nice & warm in bed (even a wet one) and it can be frightening in the dark & quiet of the night. Can she reach the light switches? Put a torch by the bed so she can shine it on the light switch to find it quickly. Or keep the bathroom & landing lights on/put nightlights in each room.
If the trek to the bathroom is too terrifying, put a potty beside the bed for a while.
Carrot - new pyjamas/nightie (get her to choose) that are not to be weed on/for best
Stick - get her to help wash the soiled bedding & nightclothes
Good luck!