Well, I'll disagree that Carol knew what she said would drive Rick to go insane and roll around bloodied in the streets ranting like a loon and randomly pointing his gun at people. No, I don't think Carol could have predicted that. I'm sure if she had an agenda, it didn't involve blatant stupidity. I also don't believe she was hellbent on Rick killing Pete, she just knew that would be the eventual outcome. Rick and Carol have been pretty much partnered up with their own agenda since arriving, her telling him what she believed to be happening with Jessie was something that needed to be communicated, IMO.