Article title should be "Grandma", which is what she's referred to in the game. Also, I don't think she's intended to be Peach's actual grandmother, and that the use of "Grandma" in the English version is a mistranslation of her Japanese name, "Obaasan", which can mean both "grandmother" or simply a respectful title to an eldery woman. (Similarly, "Ojiisan" can mean grandfather or a respectful title to an elderly man.) Given Grandma's species, I would say that she and Peach are not biologically related.
The preceding unsigned comment was added by ChrisAlassal (talk).
I agree... Maybe like my friend, she lives next to an elderly lady she calls "Grandma". Maybe this is the same thing with Peach and the elderly Toad.