Parasocial relationships are weird, but I understand why someone would be upset by the death of a beloved actor or athlete but I genuinely am mystified by anyone being at all bothered by one of the royal family dying.
She's the living embodiment of the country itself, through her position as the Queen of Canada.
I don't really care that much about the specific person herself, i don't even know much about her personally nor is it very relevant unless she brings disrespect to the position or something, but she personifies the Crown and thus the country (symbolically). She was our head of state for many decades, the royal family are mostly a bunch of snots that get far too much money, but as long as the Crown remains in place I have to pay respect as a Canadian and so should all Canadians.