They're still on-planet, you know. They also have tech we don't. (Or at least, that was the case before.) And if we hadn't traded everyone we captured away before examination, we'd have some scientists too, presumably. Luckily, based on the combat reports we mostly captured soldiers. The civilian personnel fled and weren't captured. We'll get them and their secrets later. She can give us info, be propoganda or a bargaining chip, and if we break her enough she may even become a double agent.
Of course, all /tg/ really wants to know is: is she hot?