She's older than your girl, which could poo-poo the line :( But! They are both charismatic types who try to get their way through talking first. They also both struggle with keeping people at arm's length. Perhaps they were long-distance friends (Cal is a gear head and enjoys technology, I can see her having a long distance friendship over the comms and through holographic projections, etc) And staying pals when Nat came to Terminus (Karaoke duels/Drinks at Last Spoon, anyone?)