The Valonqar Prophecy says: When your tears have drowned you, the valonqar shall wrap his hands about your pale white throat and choke the life from you.”
George R.R. Martin says ‘Valonqar’ means ‘younger sibling’, which could be either her twin brother Jaime (born after her) or Tyrion, whose relationship with Cersei is already toxic.
As last night played out, Jamie (her younger sibling) had his hands "around her throat" as she was crying and the crumbling stone choked the life out of her. So, you could say, that's exactly what happened. And, Jamie's hand placement isn't a coincidence.