I have not had a chronic bed wetter so I am not speaking from experience just making a suggestion .... What about getting a large water proof pad (a change pad but a big one) and putting it in her bed on top of the sheet and put her in the thick underwear with a plastic pant over top ..... This way you can stop the leaks as much as possible but she can still feel the wetness in hopes of it beginnibg to wake her up and then no fluids at all after 6 pm and just a sip of water when brushing teeth and of course a pee before bed. This is what I would try.