Sure, but that doesn't necessarily present a danger to you, and if it's clear that she's shooting as self-defense (and I think two young men accosting an elderly woman while physically preventing the car from moving qualifies), there's no reason for you to feel threatened.

If we put it in a non-gun context, let's say grandma pulls out a knife to defend herself from these men, and then someone sees that and immediately pulls a knife of their own and engages. Why would you do that? It's incredibly unlikely that grandma is going on a killing spree or anything, she just wants to defend herself from these aggressive individuals.