Mini-Mom is the superhero alias of Marge Simpson when she, with the rest of Springfield, is turned into a ten year old by Dr. Colossus. Like the rest of the group, she has no real super powers; however, she has a rolling pin at her disposal.
Marge Simpson was changing Maggie's diaper with Lisa when Dr. Colossus activated his Anti-chronometric responsolite consolidator (aka the Ten-inator), turning her and everyone else in town into ten year olds. She remains home and is there, along with many others when Bartman returns. She appears to come up with the plan to go to Death Mountain.
Soon Bartman leads a whole new team to Colossus' lair, consisting of Houseboy, Mature Lass, Commander Cool, Mini-Mom, The Silencer, The Laughter, The Amazing Lenny and Kid Blackula. Mini-Mom's role is small, though she helps push down the gates and laughs at Colossus with the rest of the group, causing him to de-activate the ray and send everyone back to normal.