Per her bio in the above link, Carki is an ambiguously-evil merchant who specializes in extraordinary wares; in Inmortalitas, she's also trying to sell off her ever-growing collection of weapons so gimmicky that even Daikatana would've rejected them. That thing Vince is holding (the rocket launcher/alien weapon from frustratingly-M1-only scenario Trojan) is one of the more immediately-useful ones.
She has outlets set up just about everywhere in inhabited space, and is mysteriously always manning them whenever the Rozies happen to be in the neighborhood. Like many have done before, Carki vastly underestimates Vince's intelligence, trying to sell him stuff as if he's any other trigger-happy merc.
Meta-wise, I may have taken some liberties with her design.
[Titleknown commented after posting that perhaps Carki wises up later and modifies her wares to be more utility-based, with...dubious results]