It wasn't [i]her [/i]job to deal with prisoners. See, there were two types of heroes in the world of Lady Foxfire; buddhist monks and taoist alchemists. A monk would punch an innocent foxgirl in the mouth - Foxpearl stopped meditatively. No, Lady Foxfire was [i]not [/i]innocent, as she the most virtuous of her tails well knew. She had just professed to be for so long that 'innocent foxgirl' felt like a single word. Okay, so a monk would punch a guilty foxgirl in the mouth, and then smile and bow and maybe give a koan while she picked her fangs up out of the street before leaving town for easier pickings. That was a friendly, aspirational kind of virtue. A taoist alchemist, by comparison, might exorcise you directly into one of the hells, or bury you under a bridge, or distill you into an elixir of immortality, or bind you into a candle or some other heinous shit that took years to wriggle free of. And it was all pointless because she'd never learned anything from any of it! 

If she was on the side of righteousness now she definitely wanted to model herself after the virtuous, teeth-punching monks and not the wicked, demon-binding alchemists. That was why she considered her entire exchange with Xingtian complete the moment they had lost consciousness - she wasn't going to stick around afterwards to put her in a box like a hack. And especially not when one option involved staying with a cute princess and the other involved saturating in the whale-stink of Shifu's barely miraculous transformation.

[b]Bias[/b]: Everyone involved in the prison system in any capacity is lame, actually