I'm sure you're frustrated with the many reports of predation that might have been prevented. It's distressing but please remember that there are over 40,000 members of this forum and what you're seeing is a small fraction of that. Most people do everything they can within reason and I personally wouldn't ask anyone else to do more than they can. Although I can feel some of your frustration, I agree with her; you shouldn't be judging what you can't see and she's already said she's working to improve the safety situation of her remaining chickens. She really didn't need harsh criticism right now. Your frustrations might be better voiced in another thread a little later. She obviously loves her chickens and we have no idea what she's able to do at this point or earlier. She obviously felt they were safe given her circumstances.
Something has also obviously changed in the predator situation after a whole year and since she wasn't able to see the predator in the act, that also means she probably didn't have any warning. No resident predator that I know of is going to wait a year before trying for a chicken; they're just too attractive.
What's an appropriate pen in one situation may not be in another; she's right, we shouldn't judge her situation without full knowledge of the situation and even then, now is not the time for criticism; it's the time for support. Think about how you'd feel if somehow something similar happened to you. Please be as supportive of her as you would like others to be of you.