You may have just encountered her at a bad moment. She may have just encountered someone else, moments before, who without asking tried to pet her dog, who then, because he was feeling out of sorts (they don't just wear those collars for fashion), snapped at that stranger, who then yelled at the owner. I have seen such things happen.

Maybe you will see her again some time, and have a more pleasant encounter with her AND her dog! I'd give her the benefit of the doubt, and certainly NOT take it personally!