Claire Yeh (next to Mark Johnson) did not win any event at the Nationals. However, with a rating of 423, she managed to beat three 900 players and one 700 player. I heard Jim Chai (the rightmost one) helped her during the matches but I don't think it had anything to do with her winning.:-)
I believe Claire's rating will have a very big boost, if not the biggest, after the Nationals.