Your friend's terms of service with her employer may have required her to go in. Regardless, I agree that I too would probably have shown up myself. My sense of obligation to my co-workers and workplace is pretty strong and I too fear the consequences of making my employer unhappy. Yes, while reluctant I would have turned up.

However, I would not have left you home. What were the arrangements to begin with? How had you arrived at this friend's place? Had she been expected from the outset to get you home? What alternatives were available (anyone you could have called? Your friend's mother? Taxi cab?). I think that, if it had already been agreed that she would get you home that you ought to have worked together to see that you got home.