Rosa just waited for him to calm down again, then waved a server over to bring them another round of shots. "Drink. And then stop being a little bitch."
Was she invested in Jake and Amy? Absolutely not. But they did make a pretty nice pair. Sort of evened each other out and made them both less annoying. Rosa was invested in them being less irritating.
And for what it was worth she thought Jake could totally compete with Sirius Black. They were both solid sevens.