I've got Jubilee in the Team-Building class, mainly because I feel her powers make her far more suited to working in conjunction with others, rather than on her own.  This is held up in canon, too, since she's typically paired with one or more other mutants, most often Logan.  I think they work well together because they balance one another's strengths and weaknesses, so Jubilee already has some knowledge and experience working with a team.<br/><br/>That being said, Jubilee would also offer her services to any teachers who might want her to give the students training in dodging or something.  She can adjust the impact of her energy bolts, and it has the added benefit of giving her some additional training aiming at moving targets with unpredictable patterns!