Maggie is the third of three kids to Homer and Marge, and twin sister to Lisa. When Lisa and Maggie were 8, they both volunterily left school in order to obtain jobs so that the family can raise money for a lawyer to sue Mr. Burns, who had been neglecting the stucture of the Nuclear Plant causing Homer to get radiation poisonng.

They find a job at a nearby club as waitresses, where occationally, they would sing with their brother Bart. Eventually, the lawyer would be paid for and they court proceedings start, shortly after Homer recovered. They won the case, and Lisa decided to return to school, while Maggie did not, claiming that she had everything she needed.

Lisa would eventually get her boss to fire her, as the Simpsons concluded it was the only way for her to leave the club and return to school. After a tearful discussion with Marge, Maggie understood why they did it.

At the age of 28, Maggie would become a lawyer herself, while Lisa would go on to run the club they both worked at 20 years prior, and one day while in a fast food resturant, Maggie would try to break two guys up who where having a fight and would get stabbed in the throat, dying almost instantly.