So what class is she?
Her role in this story thus far (in terms of inspiration, not story structure) is to be finally revealed as having an -- interesting ancestry, and also to help in a rescue. A complicated rescue, involving infiltrating a hostile realm, sneaking up to place of execution (the most open place where the captives will be), and then breaking them free by force, which gives her a lot of potential avenues to be useful.
Rogue was the first idea. Sorcerer's another possibility, even though her ancestry doesn't point toward that; she can have some other factor causing it. Or even druid -- she does seem to have a touch of nature-loving. And at that, I still have yet to decide what level they all are, but it's going to be high enough that she could multi-class.
Bard, maybe. . . .