[spoilers extended] A valonqar theory in show universe...

Long time lurker, first time poster, go easy on me!

There have been so many theories related to the identity of the valonqar and the the manner in which he/she kills Cersei-

Is there any available discussion on the possibility that, if we can assume that the valonqar in the prophesy does not have to be Cersei's younger sibling but any person with younger sibling status, the velonqar could be Cersei's own child? Stay with me here...

If Cersei finds herself pregnant, the child must not live, as it was told to her she would birth 3 children with golden shrouds. What if she gets pregnant and dies via childbirth, to a stillborn baby? It fulfills the prophesy. In context with her character, primarily with book!Cersei as it is better fleshed out, there would be a supreme irony in this- she deeply loathes her womanhood in so many ways, although she treasures her maternal position. To be killed in an act that is such a huge part of being a woman, while at the same time not being able to participate in the part she enjoys, motherhood, would be ironic and a departure from the normal death by treachery/deceit/betrayal... and this child would be a younger sibling to her children, fulfilling the valonqar position.

Am I crazy into the tinfoil here? Has anyone brought this possibility up before? If so, please link me in!