Try either a firm "No" or "Ah-Ah" sound, the water should be enough of a deterrent on it's own, but it's good to use a consistent word or phrase so she knows you mean business when she hears it. I also HIGHLY recommend hissing. I adopted a cat with some behavioral issues, (he gets overestimated easily and gets mouthy) so I will hiss at him and tell him "NO" when he gets fresh.
You can also try clicker training for rewarding good behavior. I know it's a more common method for training dogs, but cats are smart and since she's a kitten she might pick up to it pretty easily. You'll want to make sure you use it when she is doing what you want and reward her with treats, toys or some playtime :)