Spark aka. Spark (Patreon)

Previously to becoming a Rebel soldier Spark was an orphaned sootie in one of the Royalist Militar Zeppelins. 

"A sootie is a worker of manual labor, particularly work that involves shoveling coal and ash in boiler and engine rooms. The names comes from the fact that such workers will, inevitably, become covered in soot during their work.  Besides shoveling coal, their duties also include running rigging and repairing the outside of the balloons when needed. "

She spent all her time in the boiler room and was promoted to engineering, however after almost making the boiler blow up, she ended up deck as a deckling, as a permanent Balloon technician and the ocasional gunner. She's quite skilled into parching helium balloons and moving along the skies pendling from a rope. It was no surprise that when offered a part in the Rebellion, she begged to be able to fly around in combat. It took Bree less than a week to produce a polley system that would allow her to do that very thing.

She had to dissappear from the army after a soldier tried to grope her and she shoot him. There's still a bounty on her head, but given her permanent Soot covered physique and young age, she's believed to be a boy. Spark does laugh about how convenient that turned out to be, but it's slightly mad about the fact that the army won't admit their best balloner was a woman.