[Novo]

I don't really know a logical way how Varys would know though since it was a promise to Ned at the Tower of Joy and Ned obviously wouldn't a let it slip, think the only other person that knows about it is Howland (which is why I said before about the history of the Starks and Reeds being underestimated) but Howland has not appeared in the books or the show, (apart from the TOJ episode where they focused on him surviving) we are led to believe he is still alive (think this is why Meera is still alive and hasn't been killed off maybe an encounter is coming soon)