She knows that Britt cares for Rocco. Why not team up (temporarily) so that his support system amped up? I get that Lulu and Dante won't like Britt being Rocco's outlet but that's how it bees sometimes. The important thing is for him to get it out. Make Britt swear that she will relay back to them what Rocco is feeling. Not in a spying way, but keeping them in the loop.
Britt did not get into Rocco's head. He sought her out majority of the time. Laura pitched a great idea but none of them went for it and here we are. Rocco and Britt's bond has already formed--you can't put the toothpaste back in the tube.