During season seven, Cersei discovers she's pregnant with another Lannister heir. This renewed chance at motherhood unleashes — dare we say it — a lioness-like pride that keeps her from fully succumbing to the armistice borne from the Dragonpit Summit.
With a baby on the way, Reddit user lounaaaaaaaa predicts that Cersei may offer her child to the Night King to protect Westeros and through this sacrifice gain control of the Seven Kingdoms. Even though the move would be somewhat out of character for Cersei, since she normally puts family first, the overall theory tracks well when we think back to the introduction of Craster the wildling in the second season.
Lest we forget, Craster is the incestuous old man who lives on a secluded homestead beyond the wall where he turns his daughters into wives. This is relevant because any wife who bears a son has the child ripped from her and offered up to the White Walkers. Is this merely a cruel act or a ritualistic payment for sanctuary on the White Walker's land? If the latter, the show has already laid the groundwork for Cersei to appease the Night King should she choose. Or perhaps, after their lovemaking, Jon and Daenerys have a child of their own to sacrifice. Only time will tell.