I've wondered about precisely this scenario at other times... I think even if this is the middle of the story, sovay will end up as more than "Woman in Bookstore." I'd guess she'll become either an ally or a foe of the ditcher of the keys. Our instinct says to become an ally, since we tend to sympathize with people who are being pursued. But... we don't have all the information... and yet it's always without full information that we have to make decisions...