I doubt that Jamie is the volanquor only based on the fact that it said "hands" (no pun intended). I also doubt that Margaery is the queen in the prophesy. The prophesy says "younger and
more beautiful", whereas Margaery is said to be
as beautiful. According to Cercei, Rhaegar is more beautiful than Jamie, so Dany is probably the one that is younger
and more beautiful than Cercei. However, Sparks the Knave is right about GRRM.
