Ariel’s mother, who died before the main story, was named Athena in Disney’s The Little Mermaid continuity.
Athena’s death is shown in The Little Mermaid: Ariel’s Beginning, the 2008 prequel to the 1989 animated film. Pirates attack the mermaid family, and Athena is killed while trying to retrieve a music box. Her death devastates King Triton and leads him to outlaw music in Atlantica.
That history explains a major emotional condition at the start of the prequel: Ariel grows up in a kingdom where singing and instruments are forbidden. She eventually helps reunite the family with music, making Athena’s memory part of the story’s resolution.
Athena is not named in the 1989 theatrical film, and the 2023 live-action adaptation changes elements of Ariel’s family history. Therefore, the answer belongs specifically to the animated Disney continuity expanded by the 2008 prequel.