Not counting her enhancements, she is 1.2/3/1.2 if you're running dragons, or rather 1.44/9/1.44 if you are running her as a leader. With awakenings, add 40% water damage enhancement, not counting any subs' awakenings. Tie that in with having two fast defense buffs and... she's really damn solid. Wow, I hadn't considered that.
I wonder what her sub pool is like, though. Haven't read much into water dragons.
Edit: she gets Starling, Beyzul, Karin, Sun Quan, Awoken Orochi, Blonia, beach!Chester and Gronia, Mirage Plesios, Water Dragon Swordsman (bind removal!), Cleopatra (poison!), Leviathan, and even some less ideal stuff like the water bowl dragon for a board clearing option. Mythril also comes to mind for emergency defense (and your enhanced hp makes up for his shitty HP somewhat) and Blast Aurora Dragon (which would pop your water defense to a solid 50% and give you orb changes, and he has huge HP that you'll only further enhance). I'd list more but the monster book isn't loading well for me right now.
Overall, surprisingly fantastic for a 4*. I want her and will try to get her!
Edit2: unconventional option: Pirate king Zaerog. Fairly easy to make and packs a dragon damage boost, which will be super good considering most of these water dragons don't pack much in ATK.