itch.io

One possible solution for the mertail issue could be something along the lines of other fantasy works, where the tail divides and becomes actual legs when dry. I seem to recall a movie using this trick when dealing with mermaids, but I can't for the life of me remember the title.

EDIT: I know that this would potentially mean two separate character models to deal with in regards to a mermaid character. Another option is to simply have her legs covered in scales with small wing type fins protruding from the sides of her thighs or calves, but I don't know how your modeling software would like this idea.