I did see she went skydiving for her 80th birthday. That's enough to suggest she isn't exactly frail.
Simply stating "43kg and 95yo" doesn't mean incapable of harming others. It's a silly argument to try to make actually.
Again, context on the situation is what's necessary to determine if reasonable force was used. Everything else, including assumptions that 43kg == incapable of harming others is silly.
