Sprinkler Park

I shot this in the middle of the day. Is there anything I could have done different with

the lighting that would have made it more effective?

Well, you could have tried using a reflector to add a little fill light but I honestly think this looks good the way it is. My only suggestion (and its very subjective) would be to frame it differently. Because she's closer to the left hand side and also facing left, there's a lot of empty space to the right. Adding that space on the side the subject is facing is sort of the norm with some exceptions. In this case, I think it would have made the lighting more interesting because the background is darker on the left highlighting the water drops. Just my two cents.