The principle is that free people can travel where they wish.
However, given that Rose Kelley is a ward of the State, I can’t fault Canada for deciding to keep another country’s parasites out, if they’re going to keep anyone out. Yes, it sucks that she has friends and family in Canada and can’t see them. It also sucks that she’s mooching from the taxpayers of Michigan. She could change one by changing the other.
If Canada didn’t have their own class of cheesesuckers, there’d be no reason for them to do this. So which government is at greater fault here?