Ok, I'm out of ideas. O is leaking big time nearly every night. She's 22m, ready to daytime train, but she has kidney issues that necessitate water being available all of the time. So she sleeps with her straw cup and usually drinks 12-16 oz overnight.

We currently use target overnight diapers. Huggies overnights leak horribly. Sizing up doesn't seem to help. I've tried a few cloth combos and haven't found a good enough fit to prevent leaks. I think she pees a lot all at once, because sometimes the cloth diapers aren't even full when they leak. So maybe something that absorbs super fast?

Any other ideas?