The title says bed wetting or does she also do it during the day ? Punishing for wetting doesnt work it creates an anxiety,hence hiding the underwear, If she is doing this at nights cut back on all liquids after early eveing, as children do want to drink a lot before bed, the doctor is right and she will grow out of it, at 5 year old does she go to many camps or friends over night ? relax a bit make less of an issue , sometimes just taking that step back helps .Good Luck