Sharon Marsh (née Kimble) is Stan and Shelly Marsh's mother, as well as Randy Marsh's wife. She first appeared in the Season One episode, "An Elephant Makes Love to a Pig".
There are roughly one-sh*t billion tropes so PLEASE look through them before adding one. Otherwise add what you like. ADDITION: PLEASE read through the trope description provided before submitting something. It's not a huge deal but too often people submit characters that don't fit just because they misinterpreted the title...