C.S.
First off, she does not ned to be having a glass of milk in the middle of the night. There is no way she needs that amount of liquid in the middle of the night. And why are you changing her diaper in the middle of the night as well? If it is because she is wet, then restrict her liquids before bed. At two perhaps you can think of potty training for the day time which you can then phase into the nighttime routine.