Supposedly, IOTL, before her marriage to Ernest Augustus of Brunswick-Luneburg, Sophia of Hanover (mother of King George I of Britain) was courted by her first cousin, Charles Stuart. IOTL, she rebuffed him because she thought he was trying to get money from one of her mother's supporters.
What if Sophia had married Charles and become Queen of England instead of Catherine of Braganza? Neither had any fertility problems, so an heir would be likely.
Any thoughts?