That she's pretty much a supporting character with no real "character" to her aside from spouting expositional dialogue and sometimes getting knocked around by the villain of the week. What, was Winn busy that week spouting expositional dialogue and getting knocked around somewhere else?
That said, Briana Venskus has been around of late. She was on The Walking Dead in one episode this season (so far?), and was even BACK on Agents of SHIELD in the opener episode this season. I guess the producers on Supergirl like her enough to bring her up for a minor job, which I'm guessing any local actor should be able to fulfill (full dues to Briana of course, she's standout-ish enough that we're even talking about her!).
Perhaps she's been taking care of their old base all this time.
