Would she still have all her agents, The Friends of Red Jenny or do you think she would be by herself?
I agree that she wouldn't be in the military or a common merc though. If she was by herself, I could see her being like Kasumi and doing her own thing.
I guess that depends. People in Mass Effect benefit greatly from having advanced technology at their disposal, which people can steal and use to their own ends, which is pretty much what Kasumi does. With the right equipment, you can gather information, siphon funds and do all sorts of tech-savvy shenanigans to give all kinds of people a hard time all by yourself. On top of that, within the framework of that universe, a "Red Jenny" equivalent can basically be much more focused, since they're not working on behalf of some mistreated servants and the sort. They'd just target corrupt politicians, or politicians in general, CEO's of corporations they dislike or fabulously wealthy murderous scumbags like Donovan Hock. I imagine they'd be in it more for the thrill and the fun and of course for the insane amounts of money.
I for one sincerely wish we could play such a role ourselves in either DA or ME. I'd love to be in control of a swashbuckling scoundrel that gives these sorts of people a hard time, and occasionally plonks one when the occasion calls for it.