Aunt Maria

Aunt Maria is an aunt of Mario and Luigi's who was briefly mentioned by Luigi in The Adventures of Super Mario Bros. 3 episode "Crimes R Us".

While Mario and Luigi were looking at clouds, Luigi noticed that one cloud in particular resembled their Aunt Maria. However, the cloud looked nothing like a human. Aside from this instance, no other mention of Aunt Maria was ever made.

It's possible that Aunt Maria is the namesake of Mario, due to the similarities of their names.