I can't speak for others, but U.S. domestic policy often directly impacts Canadian day to day life.Many of you commenting or sharing stories in this very thread aren't even from the US, which is also strange as you have literally no stake in her mostly domestic policy planks.
As far as I can tell the reason she's such a big deal is that she checks all the "She'll be the one to beat the old white guys" boxes. Personally when I see some of the ideas passed of by her and seconded by others it makes me extremely concerned for the well being of both America and the rest of the world.
Yes, I felt the same way about Trump during the 2016 election.