Lana robs banks with her mom Lori Baumgartner; it seems that she does all the work with her blast power. When they were arrested last time, Lana was separated from her mother, who was imprisoned. The judges believed that her mother influenced her to rob banks, as she's still under-age.
Bombshell was created by Brian Michael Bendis and David Lafuente and first appeared in Ultimate (Comics) Spider-Man #2 (2009). She was part of the Ultimate Universe, but was transported to the Prime Marvel Universe (616) after the events of Secret Wars.
Major Story Arcs
Going to School
Bombshell, under her human name Lana Baumgartner went to the same school as Peter Parker for a short while, where she is recognized - but convinces Peter and his friends to keep quiet about her super-villainous exploits. For some time, Lana kept commiting crimes with her mother, and ocassionaly fighting Spider-Man. But because of her contact with Spider-Man, she starts seeing the errors of her ways and slowely changed her attidute.
Years later, after Peter Parker (Spider-man)'s death, Lana becomes part of the All-New Ultimates, alongside The New Spider-Man (Miles Morales), Kitty Pryde, Spider-Woman, Cloak and Dagger. This is the first time she actually starts acting heroicly, in honor of the original Spider-Man of her universe.
Coming to Earth 616
After the events of Secret Wars in which all of reality was destroyed and reshaped once more, Lana is transported to the main Marvel universe (Universe 616). Somhow unknown that she transported universes, she attended the same school as Miles Moralles (whom was also transported to this universe). She was seen teaming up with Miles Morales and Goldballs. Eventually, she also joined Miles' superhero team, the Champions.