One of the mermaids in Peter Pan was Ariel's mother.
Bare with me on this one guys, I know it sounds farfetched, but Reddit user ghtw3 suggested it, and I have to say, the evidence is all there.
They look very similar
Visually, the mermaid from Peter Pan looks very similar to Ariel, especially with her red hair. In the 2008 film, The Little Mermaid: Ariel's Beginning we saw Ariel's mother, Athena, at the very beginning before she died. This is what she looked like:
Pretty similar right? The same red hair, and the tail is even blue like the mermaid in Peter Pan. She has a necklace and a crown in Ariel's Beginning but this could be put down to marrying King Triton, becoming royalty, and having access to more jewels.