Joking completely aside.See my edit. I actually edited it twice. I've been hitting Post Reply early lately, and I'm not sure why.
But it was obviously a trick question. I consider myself to be a pretty big Zelda fan. I would have said "Left hand in most games", without even realizing he said Zelda instead of Link. It's one of those things you just don't expect.
How would we know if Reggie really wanted to know what hand she weilds the Master Sword? I'm willing to accept I'm wrong on this but based on my evidence and past experience with the titles she's either ambidextrous or right handed. Outside of her role of being a princess I have my doubts she would have time to be trained in sword fighting proficiently enough to come close to weilding in each hand. Just to play it safe I'm saying both hands but again I'm willing to accept I'm wrong on this.