Some of you are forgetting something, she didn't just kill those guys for herself, they told her straight up that they knew exactly where Alexandria was, and that hey have been watching them. They were clearly a threat not just to her, but to everyone at ASZ that she loves.
Something is clearly going to go down between her and Morgan, I have no idea what, but I do think the whole running away thing was to get them both out of ASZ.
I think it's less that she can't kill any more than she doesn't want to kill and still see the people she loves die. Maybe she thinks they are all doomed anyway and she can't intentionally kill more people and watch her family die as well - she doesn't want to go to war.

 

But what if Sophia was still alive? Would Carol be all "screw you Sophia I'm going it alone because I just can't kill for you anymore." No chance. Rick's group are like family to her now, it makes no sense why she would leave them. Totally out of character.

 

I think it is more likely that Carol and Morgan end up with the folks they have been seeing in the special armor and riding the horses...those of us who read the comics know this is going to add a nice element to the story, and I could see it being a place where both of them could be very good fits in, with how they view the world. Could also mean that they will not be major players in the next season for a while...but bring them back for big arcs that will be nice additions.

 

That's what makes her story so great -- open to many different interpretations. I think Carol has become the most controversial character since -- well, maybe Shane?

 

They have ruined her character so I wish they'd just kill her already because it makes no sense. She can't or doesn't want to kill yet goes to all the trouble of making a concealed automatic weapons holster up her sleeve to do what? Inflict mass casualties!