Poor Jubilee. Like a lot (most) Marvel Characters she has had her life and her background mangled and twisted over time by the writers. She was a mutant. Lost her mutant powers and became a technology based superhero called Wondra. Then got turned into a vampire and now from what I understand she is an orphaned baby.

The best, happiest Jubilation "Jubilee" Lee (and my Jubilee) was on the 1990s X-Men animated series. Before she appeared there she was created by Chris Claremont and Marc Silvestri. I was under the impression that she was created for the TV series but I was wrong. She showed up in Uncanny X-Men #244 in 1989 before she showed up in the 1992 TV series.
A lot of people really didn’t like Jubilee and I cant blame them. One...she was used as a replacement for Kitty Pryde. Why not just use Kitty? Two...she shot fireworks out of her hands, big deal. Dazzler did that way better.

But as usual with the X-Men writers, they figured out a way to make Jubilee more powerful and of course, "one of the most powerful mutants in the WORLD!" They all are right? Anyway it was discovered that Jub's little firecrackers, well....with concentration she could create that same effect on a sub-atomic level. That would cause a detonation like a thermonuclear bomb. Boom. She could also project her little fireworks into a human brain, giving the target basically a massive stroke. Boom.
Of course with Marvel changing everything all that is gone. But it is fun to think that little teenage, bubblegum bubble blowing Jubilee could flatten an entire city if she had to.

Jubilee - Marvel Comics