Based on your ref picture, since I don't know the character, I think I'd make a hoodless cloak and add a hat. The bodice is quite steampunk as is (particularly the darker, punkier side of steampunk), maybe adding an underbust corset or swiss waist/waspie. Moving the decorations on the skirt strips to a hip-slung utility belt might work well, or even, to keep the pattern, a pair of criss-crossed belts reaching from each hip around to the other thigh? It's a little punk, with an echo of bondage clothing, but I think in the right material, and grunged up a bit, it could fit the steam as well.
Masks are pretty popular in steampunk as well, so maybe doing that instead of facepaint?