Haibara is actually terrible for showing respect, but she is great at following social conventions. It balances out, sometimes. It is, at the very least, acknowledgement of Azula's station, which seems like enough for now.

"As far as I've seen, actual violence is fairly rare. We're all intensely aware of the fact we're in tight confines and there's no getting away from other passengers or from consequences."

Haibara can't help to think about her own situation. The woman who wants very intensely to murder Haibara is, after all, on this train. And Haibara is relying on this very notion to keep her safe. It's not as reassuring as she makes it sound.