Yes, Cersei's son Tommen died at the end of season six, but YouTuber bridge4 has put forth an elaborate theory that Tommen's memory will cause the Queen's death. In bridge4's theory, Cersei survives the Great War as prisoner of the Starks and Targaryens only to take her own life once she finally admits to herself that her actions at the Sept of Baelor led to Tommen's demise.
Although the concept of Cersei's suicide doesn't exactly fall in line with Maggy's prophecy, bridge4's theory does lend a metaphorical nod to the witch's warning since Tommen is Cersei's youngest child. On the other hand, there are several Reddit theories that speak to the literal idea of Tommen wrapping his hands around his mother's pale white throat — though many of these involve a reanimated version of Tommen by either Qyburn or the Night King. We, however, prefer the poetic justice of this YouTube theory as it ties Cersei's demise into her overall story arc of a mother driven to madness.