I've headcanoned Willow as an education major since they had her teaching Jenny's class. Willow is so set up to follow in Jenny's footsteps. She's good with computers, likes magic, and likes to teach. Season three had that subplot of her tutoring one of the jocks, which just cemented in my mind that they were trying to foreshadow her going into teaching, but then they never actually confirmed what her major was, and then seasons six and seven basically drop any college related plotlines entirely.
In the world where season seven is good, I think Willow is a student teacher at Sunnydale High; it would be her senior year of college, unless the events of season six put her behind (very likely, but let's pretend it doesn't since the writers clearly don't actually care about those kinds of consequences), and that's usually when education majors have to do student teaching. This puts her and Buffy in mentorship roles at the high school while Dawn was a student there, and Xander was doing construction work on campus. All of the Scoobies except Anya would be back at the school, and I think returning to the theme of "high school is hell" should have been the necessary follow-up to the melodrama of season six. Taking the plots back to basics while the Scoobies have a more mature perspective on things.