It's been over an hour since you first post; is she still doing it? That certainly is how my toads have acted while getting ready to shed, and she DOES have that appropriately dull pre-shed coloration. If she's still having trouble an hour later, well... That'd be a record for me, at least. The fact she's in water would make sense.

Sorry this isn't really of more help, but it sure looks normal at first glance.