It would be prudent to arrange an evaluation for her with a mental health clincian. You might also consider some testing, such as a neuropsychological evaluation. While she is undoubtedly intelligent, there may be some learning obstacle that accounts for her uneven school performance. What treatments have been attempted to address the nocturnal enuresis?
Not that I am an expert on this subject but I wet the bed when I was younger and didn't stop until I was a teenager. I was never great at school but somehow managed to scoot by unnoticed. After high school graduation I went to a community college until my grades were good enough for exceptance into a large university- which I graduated from and went on to have a fufilling career and a wonderful family. The reason I'm writing this is because things do turn around. Drawing too much attention to the bedwetting can actually make it worse in my oppinion. I think there is an emotional aspect to it that your daughter doesn't have control over. My parents took me to every expert across the state and never came up with a solution. If you read about enuresis one of the things you will find is hiding clothes and sheets is all part of it- not sure why- I think for me it was shame and embarassment. Good luck! If you have not found a medical reason for the bed wetting I bet your daughter will outgrow it soon.