Well, the character in question isn't quite a mermaid, but instead a Naiad. I was considering an Undine, but I settled on Naiadbecause they're not nearly so common as merfolk.
Oh, that makes more sense. The original post said mermaid, so that is the part my brain was focusing on. It does make a bit of sense now that you have clarified that it will not be a traditional mermaid, and I wish you luck on figuring out a solution.
