I know virtually nothing about Firewall beyond what I learned playing the now-defunct G.I. Joe Battleground mobile game: she's a hacker, a pistol expert, and trained under Mainframe.
I never read the Devil's Due G.I. Joe comics, but it seems like that version has pigtails and gets tied up or something? And she has a role in one of the G.I. Joe \ Transformers crossover?
I used the Heroclix Sasha Bordeaux, even though the pants weren't quite right. Also, I seem to have forgotten to give her gloves.
Maybe this is her casual uniform?