My girl was giving an obvious shit-test by bringing up in a group conversation that a mutual friend of all ours was "So hot."

I felt I reacted well by rolling with it in the moment, then later that night confronting her in a calm and assertive way and telling her her behavior was unacceptable. That went well, she apologized and was obviously loving being told off.

Then she busted on me the "you don't need to be jealous", but in a cunning way. She strung it in to a sentence that went elsewhere. This is actually a common shit-test in itself and something I see in negotiations at work. The person talking will work in a point of conflict and then try to bury it with a quick few sentences to take the conversation away from that point. In order to re-butt the point you have to be confident enough to either interrupt them(which can be daunting if they're in the middle of a presentation because some people will consider it rude behavior etc.), or be willing to call them out on it once they get to the end of what they/re saying. The Beta behavior is to let it slide, the Alpha is to call them out.

Shit-test one: So and so is "So Hot". To see if I react.
Shit-test two: You don't need to be jealous.(The "you're being emotional shit-test is a go-to)
Shit-test three: The Buried Burr. Be ready to come back to the point of conflict and call her out. Don't let her(or him, this applies to any negotiation) to distract you from the issue.