[AsoIaF/A Game of Thrones] What if Robert discovered that Cersei was aborting their own children early on in their marriage?
Cersei Lannister was certainly one of if not THE worst possible Queens in the entire series. It was ultimately her who is responsible for the majority of the strife that happened in the series/ Cirsei aborted every baby that was actually Robert's, and keeping the ones who were by her incestuous lover, Jaime, thereby ending the new royal line by ensuring that NONE of the heirs were legitimate.
If Robert sniffed this out early enough, like oh say, 2 years into their marriage, and he executed Cersei for being an asshole, then how would this change the story, from Robert's selection of a new Queen immediately after the execution afterward?