Rockstar Maggie is Maggie Simpson's adult form from "Holidays of Future Passed". She is the lead singer and electric guitarist for her rock band and is known as "The Voice of Her Generation", although like any time she appears in the future her voice, ironically, is never heard.
As seen in a thirty year photo montage, in her late teen years Maggie appeared to not go to college and appeared angry or bored in Christmas photos. When she was 20 she was shown smiling and holding a guitar, showing a new passion for music, and the following year she is dressed in an extravagant rock star outfit. The year after it is shown Maggie became a famous rock star, as Marge holds a poster for one of her concerts. In 2041 a Christmas photo from Maggie shows her performing at a Christmas themed concert with her formed band from presumably at least the year prior, and the photo is captioned Maggie Simpson - The Voice of Her Generation.
In the episode, Maggie is on tour and is staying at the Benny Hilton in London, She is pregnant with her baby due soon, but to the disappointment of her band her doctor says she cannot make a sound until the baby comes, as new research reveals the umbilical cord is also a vocal cord. When asked, the band refuses to say who the father is, hinting that one of them may be the father and that Maggie had sex with all of them.
Maggie tries to teleport home to spend Christmas with her family, but she cannot due to being pregnant and must fly by airplane. Planes now appear very outdated and run down while the flight crew appear as Mad Max-esque and serve things like suicide pills and dog food.
An exhausted Maggie finally arrives in Springfield for Christmas Eve and gets a cab driven by Kearny, where she begins to have contractions. He takes her to the hospital, where they tell him there’s no room at the In-patient facility. Kearny protests, saying Maggie just played a sold out show in Beijing. The nurse, after calling Maggie a star in the east, gets her a room in the Manger wing. Instead of an epidural, Dr. Hibbert gives her a pacifier, which does help relieve her.
Marge arrives at the hospital shortly afterwards, and the next day, on Christmas morning, she and Maggie return home with Maggie's baby, a daughter who looks just like her, including sucking on a red pacifier. When a newly unfrozen Grandpa asks who the father is, she opens her mouth to speak but is cutoff by him, saying if there’s one day single mothers need a break, it’s Christmas.
She and her family then pose for a Christmas photo
Maggie makes a brief cameo in "Days of Future Future", where she is seen at a restaurant on a date with Gerald Samson, and the two share a drink. This could also make Gerald the possible father of Maggie's daughter.
Maggie grows up bearing a near identical appearance to her older sister, Lisa, although Maggie's hair is longer and instead of styling it back the first three points her hair is in fall foreword, and as an adult she has seven points instead of eight. She also has three eyelashes on each eye instead of four. After Maggie becomes a rockstar during the 30 year photo montage she is seen in different outfits. The first outfit she wears, along with the one she wears in Tapped Out, is a sparkly short purple leotard dress, that has a hole in the middle that exposes her stomach, long light purple gloves with green lighting bolts, black and purple platform boots, large black shoulder pads with spikes, green lighting bolt earrings, and green sunglasses worn narrowed down. She wears red lipstick and her hair is styled back.
In the poster Marge holds that advertises one of her concerts, she wears a dress that resembles bubbles, and she wears long blue visor sunglasses. Her hair is longer and slightly resembles her teenage self's hair from Lisa's Wedding.
In another photo showing her playing at a Christmas themed concert, she wears a red and white Santa-like dress, with black boots, grey arm bands, red triangle earrings, and a necklace with a gold pendant. Her hair is styled like her first costume.
Outside of the photo montage she is shown wearing blue sweaters with red triangle earrings. She is pregnant for most of the episode, in which her stomach hangs out of her shirts. Until she gets checked into the hospital her hair is worn in a more disheveled fashion.
- In Lisa's Wedding, future Maggie also was revealed to have a talent for singing, although in that episode we don’t hear her either.