Actually, just take it to the council. I'm thinking that a lot of the council might think she was making the right choice in regards to the protection of the group. Carol was an asset. Rick doesn't seem to be someone that can be trusted, he constantly switches his tactics. Find something that works, and stick to it. I think Carol was tired of Rick changing his mind about how things should be run; then, deciding that he doesn't want anything to do with the running of the prison. Then, he suddenly decides he has the right to make this decision without consulting anyone else.
Rick is the problem.
Also, Rick said he made the decision for himself—remember? I don’t think he really had the right to banish a “founding” member of the group for personal reasons.
Carol has come so far, from being a burden to an asset. She can even pop a limb back into its socket! But her coldness does trouble me, I admit.
Rick versus the council should be an immediate issue. Carroll was on the council. And so was Darryl who had some big feelings for her. But for now there is latitude for Darryl and Machone. I see it coming.