Emily already has Canadian citizenship. Poppa Hughes, who is Canadian, put in applications for the entire family based on their time spent in Canada over the years (his entire family lives there). The Hughes kids got their Canadian passport several years ago.
So if Emily decides she wants to skate for Canada, there's nothing the USFS can do about it. And if it's a choice of 'image' vs. skating at the Olympics again, I think image bites the dust. I doubt very much if Emily would be able to make the Olympic team in the US in 2010.