Grandma

Grandma is a minor character in the game Super Mario RPG: Legend of the Seven Stars. During the game, she dresses up as the princess so Toadstool can sneak out of the castle and join Mario on his adventure to defeat Smithy and recover the seven Star Pieces. She and Toadstool are the only ones who know about Toadstool's ???.

Relationship with Toadstool
Grandma is a Toad in this game, which may mean that Toadstool is not fully human. In fact, it may mean that Princess Toadstool is at least one-fourth Toad. Furthermore, the name "Grandma" could merely be a term of endearment used by Toadstool, not describing an actual blood relationship. In fact, the name "Grandma" is a literal translation of her Japanese title "Obaasan," which can mean both "grandmother" or a respectful title for an elderly woman. Indeed, the Super Mario RPG: Legend of the Seven Stars Nintendo Player's Guide simply refers to this character as the "chambermaid," Sadly, this cultural term simply doesn't translate over, and still to this day there are debates on the American side of fandom as to whether Peach is a Toad or not.