The article is a little bit unclear, but it sounds like she wanted to cross into Canada and do the same thing, but Canada instructed her to return to the US and reapply in the proper category, and then the US presumably asked more questions and determined that her stay in the US was likely on the wrong visa too.
But I don't understand why the US wouldn't send her home to the UK? How many days of detention does it take to equal a flight home? Also seems weird that Canada wouldn't let her in, or offer to send her home, given Canada and UK have the same King.