As you know, they usually appear MUCH larger than they really are....especially in the dark....I'm sure your border collie is canny enough to hold her own. Amazes me that I have seen more coyotes in Mississauga and GTA than in rural area I live in....in fact while I hear them, I've never seen them. Not even as road kill.
I notice the reign of terror in the Beaches has subsided...I understand the army was on standby lol.....