Spoiler (click to show/hide):
I think they just call it cash in the movies but could be wrong. Roll is a 12, so she has three dollars.
Kayin is somewhat surprised to find that she has a wallet, let alone that she has any cash. She certainly didn't remember feeling such on her person earlier, but maybe she wasn't paying the best attention. Fortunately, she finds that she has three dollars on her person, and pays the fare as she boards alongside the others. She of course frowns as she takes in the fact that she now only has a quarter to her name, short of finding out she has money elsewhere she doesn't know about.
Once on though, Kayin briefly tries to think about who to sit next to or near to, and winds up settling on Sunset, assuming the spot next to her had not already been claimed.