Cate's family is from town and she has siblings who are most likely close to Fitz's age, so I'm sure they are familiar with one another. Plus she works the bar, so.
Nat's only a few years older, and they both grew up in town, so I'm sure they know one another. Possible history there!
He and Felix are the same age, but grew up on different continents, so unfortunately that doesn't give us connections. I'm sure they'll run into one another at the reserve, though?