Years ago when I was in a used bookstore I remember taking a glance at a Little Mermaid book which had a nice art style and was surprised that it had a happy ending.

It was one of those tall rectangular books, and I think that it had a dustjacket. I think the little mermaid had dark hair with a brightly colored tail, perhaps orange. I definitely recall that she was underwater. For the record, the art style and design of the cover resembled these covers.

https://m.media-amazon.com/images/I/61rHW8MNTYL._AC_UF1000,1000_QL80_.jpg

https://m.media-amazon.com/images/I/A1xkbX-J1jL._AC_UF1000,1000_QL80_.jpg

I sadly can't remember much about it aside from one thing, how the story had a happy ending. When the Sea Witch gave the Little Mermaid legs in exchange for her voice she used it to replace her own voice. Unfortunately for her she found that she couldn't control her pets. The only way to get rid of it was to give it back to the Little Mermaid, which she did saying something like "You can keep your legs just take back your voice!" I remember the illustration of the Sea Witch's reaction to this, I think that she had a hand around her throat.

Finally I think that it was around 2003 when this happened, I suspect that the book was originally published in the 90s or possibly a decade before then.

If anybody could possibly tell me who did this book, I would be eternally grateful. I have spent the past couple days searching for it online but talk about trying to find a needle in a haystack.