5. Clara Is Susan's Mother
This is a theory arising from an interesting shot of Clara, her leaf and her reflection being Susan Foreman the Doctor's Granddaughter. We know that Clara isn't the Doctor's daughter... not unless the various flashbacks of her parents meeting were complete phooey. So instead the theory goes that Clara represents the other side of the family tree (see the leaf) of Susan. The specifics of the theory is that her beau would be the son of the Doctor and River Song. I guess that might have happened the Doctor and River certainly had off screen adventures that were referred to, and they left Amy and Rory behind a bunch of times. So there is the possibility that there is a son running around out there somewhere that he simply hasn't bothered to mention to anyone. However, it does smack a bit of science fiction series staples to introduce a family relation of a character that has never once mentioned them. In summary, I'm not opposed to the theory certainly there isn't anything to say that it isn't so to the general idea of Clara being Susan's mother. In fact it makes her less of a single surprise character. As for the son of the Doctor thing... I'm not struck. I dislike the notion that he's left his son somewhere. I just find it unsettling. Besides, the reflection thing has pretty much been explained away. It isn't Susan the reflection is actually a poorly photoshopped image that originally had Sarah-Jane in it instead of Clara, and that's whose reflection it is. Oh well.