Sometimes she is a cheerleader in high-school, using "The F Word" as the jump-off point for the AU. Unfortunately, though I remember Jane as a cheerleader in one or two AU tales, I cannot find them now. Duh. Jane as a teacher appears in a few post-canon stories, like Robert Nowall's Daria: 2010 series and, again, Falling Into College.
What else could Jane be, playing off on what the show gave us? Action/adventure fanfics often have Jane in a major role. She just seems like that sort of girl. Several fanfics have generously destroyed the world so she becomes a survivalist/soldier ("Apocalyptic Daria," by Doggieboy, and "Lambda," by SigDiff). These spin off nicely from Jane's "I'm a survivor" comment in "Speedtrapped." The superhero angle is well explored in "Daria’s Web," by Fezenclop; the Legion of Lawndale Heroes series, by Roentgen and Brother Grimace; and "Lawndale’s Finest: The Last Daughter of Krypton," by NightGoblyn. She's an amateur wizard in several Harry Potter crossovers and a time-traveller in some Doctor Who crossovers.
The alter-ego picture of the "Good Mornings with Daria and Jane Show" from Is It College Yet? spawned a number of television-personality adult Janes. Then there's her active dating life, which (alas) results in her becoming a teen hooker in NightGoblyn's "The Misery Chicks." I guess the weirdest one was the emo-nerd Jane from NightGoblyn's "Exchange Students." Wait, I forgot about the submarine commander Jane from Wildgoose's Submariner series. That was very weird. (I'm not counting the "John Lanes" because they turn out a lot like the "Jane Lanes.")
My question here is, what else is possible, either in AU or future tales? Maybe reality has a clue here. What happens to most aspiring artists who leave high school? Do they starve? Fade away? Sell life insurance? (Let's don't bring up the hooker thing again.) Ideas are welcome for other alternate Janes, as is more fanfic and fan art on this topic.