Well, if it's appropriate wear for, say, a boot party, then it's definatly a boot. Anything else is suspect.
Until this answer is found this thread will stay open 24/7. I'm even trying to obtain a grant from the government so I can sit on my ass and smoke pot all day while I research this mind boggling question.
Well now this thread has some reason. In my opinion, it's based on the company, whether they call it a boot or a shoe.
But we can't have each company set their own slandered because things could get all willy-nilly. One company would be calling something a boot that another would call a shoe and then there'd be the boot-shoe riot of 2012 caused by all that end of the world talk.
Oh. I kept reading the title wrong...I read it as "At what point does she become a boot". Now that I'm not stuck on stupid and can fucking read, I still don't get the joke here. If there is one?