J.M.
My oldest son did not stay dry at night until age 7, my second is almost 7 1/2 and still not dry at night, and my youngest son is 3 1/2 and still not dry at night. (My daughter is not potty trained yet.) I tried absolutely everything. restriciting fluid, food, constant bathrooming, you name it, we tried it. Finally after tons of frustration and even more laundry, we resorted to pull-ups and time. Finally my oldest is dry, my second is getting there, and my youngest, who knows! Lots of praise when they stay dry and make them strip the wet sheets (the pull-ups are not full proof, they leak) and have them help you remake the bed, or do it themselves if they are old enough.