As JR sees how everyone's life would have unfolded had he never existed, he gets to see Cally in as an unhappy wife and mother, married to an abusive husband. In the end, she ends up killing him because he was about to beat her and the children they had. Cally's life is not contingent with whether or not JR ever existed because all of this would have happened anyway had he never made the trip to Haleyville and met her there.