She can't tell from his stoic bearing if he's actually listening to what's coming out of his mouth, but Shepard certainly is. She cocks her head when he says it; an employee, technically. That's not a soldier, to her mind, that's... a mercenary.

A loyal one. One who's only had one employer? Started young, and had no other options...

"A power company with a private army?" If she sounds dubious, it's because she is, "That's not a new one for me, believe it or not, but unless there's some context I'm not getting here... How is that different from being a merc?"