Your Grandma was created in A.D 23, not long after Mario was rehired by Nintendo, taking over from New Mario. This led New Mario to conquer the planet of Ninjatsu in the Teapot Galaxy, then created an army of Evil Burritos to destroy Nintendo, Your Grandma was one of these burritos. When the plan failed Your Grandma and the other burritos fled to earth and brainwashed peoples' parents into thinking she was one/both (Don't do it yourself kids *wink, wink*) of your parent's parents, or in some cases parent's parent's parent. Be wary kids she could attack at any second...
Death and Rebirth
Your Grandma once got into a fight with Megaman and Mother Brain. All they had to do was hit her with their most powerful attacks. When the mist cleared, Grandma was nowhere to be seen. She had died and her human body were being teleported to the very little known Earth. When she arrived, she was reborn. Sadly, she could not go into burrito form, meaning that she could not take over Earth. She just settled in and lives in the sewers.
She will die once more. 20,000 years later, she will turn into a toaster cat robot and terroize the planet of Popcornia. (????) She kills half, until she stubs her toe. She is sent to Mars, where she eats an alien and shrinks into bacteria. She blasts off again, only to realize she is powerless now. She lands on Earth once more in the shape of a burger. She is chased by an hunry mob, and turns into an innocent dog. An Idiot mistakes her for a soccer ball and kicks her into space yet again. She is turned into a fat guy, where she is gunned down by more aliens. She then turns into Cheese, and falls to a currently unknown planet, where she is eatened by a bunch of Rabid Cows. (???????????)