The preview we got from Invincible Iron Man 10 shows Emma going after Feilong and taking off her ring. So maybe that issue will show the conversation between Emma and Tony where this issue had the conversation between Emma and Kate (please have them work together/team up during Fall of X still).
What's unclear is why she didn't just say no. I'm thinking its because she still wanted the ring to prevent Orchis from seeing her when she would go with Kate but couldn't get it.
It's implied to be Kate's idea since we see a conversation between Kate and Emma on horseback after she gets resurrected and Kate has Emma read her mind about her plan for Shaw before Emma says her own. Maybe Emma wouldn't have told everyone about what happened, but IMO its pretty obvious there.