User blog comment:Jkphantom9/Cinder is NOT Blake's mom/@comment-24.94.93.179-20140722110253/@comment-10390252-20140722111343

Blame George Lucas... No, it isn't really his fault. The trope of the villain being somehow connected to the main protagonist, usually as a long-lost family member has been a part of story telling for centuries. However, I'm pretty sure that it's the thought of Cinder being the Vader to Ruby's Luke that's the main driver of that theory (I know it is for me - I just love the idea of Ruby ultimately redeeming Cinder because of their connection).