Here's my guess she's not dead and neither is Laurie. I'm guessing Carl did not shot his mother to finish her off. Remember Rick found the slug in last nights episode. That walking didn't eat her(the one Rick was stabbing in the belly) as they're trying to make you believe. My bet Carol found her kept her alive after the C section. They went out of the way to show her practicing giving a C section to that dead walker a couple of episode ago. at least that's what I'm thinking and that's who is calling on the phone as last nights show went off.