As a former bed-wetter myself, I ask that you please not refuse your child beverages. If a person feels thirst, that is the body telling them that dehydration has already begun.
As a parent of a (7 1/2 yr old) bed-wetter, I really do understand your position. It doesn't matter what we do, as the parents, to get him to NOT wet the bed. It is a physical thing, when he enters a deep sleep, his bladder releases-Dr says maybe because the rest of his body is so relaxed, possibly his bladder just relaxes as well.
If your child was unable to stand on their head by a certain age, would you want to 'fix' that? Inability to stand on one's head and inability to have a dry night are BOTH physical things that will sort themselves out with time. I don't know if this is a very good analogy (having a feeling it probably isn't, but can't think of anything else at this time of night, lol) but maybe you get the point?
BTW-I wet the bed until I was 10 and the worst part of it, for me, was being denied drinks after dinner for years-I remember some nights being SO thirsty I could hardly get to sleep, even sneaking in to the bathroom and getting sips of water from the sink after my parents went to bed. I feel it is cruel to punish a child for something that is beyond their control, and I've never met anyone who WANTED to wet the bed, so I feel it's safe to assume that wet nights are out of one's control.
Buy pull ups, try reusable (or disposable) bed liners, teach her to clean up after herself-just because she can't help it doesn't mean she shouldn't clean up after it (it IS her body after all) but PLEASE don't punish her by disrupting her sleep or dehydrating her, it's not her fault.