About half the artists I came across made something to depict Ariel as a human child, and this despite the fact that she didn't become human until her teens.
But then I figured "What the heck?"...so I decided to make this fan art of Ariel and Eric as children taking a nice walk along a beach.
The swimsuits I designed for them reflect the colors of the outfits they wore in the movie: green and purple for Ariel's top and tail, and black and red for Eric's pants.
Hope you like this!

Characters created by the Disney studios.