I’m going this weekend and taking my 10 and 13 year old, they’ve seen nearly all the recent spate of Marvel films (even better seeing the cameos as we’ve met Stan Lee!) and a few DC. They know that the violence and death is fake. The things they find scary are real life crimes and tragedies, having to perform lock down drills at school.
My parents let me watch horror movies like Friday the 13th and A Nightmare on Elm Street when I was 10, most of my friends had seen them too at that age. We knew it was fake.
I wouldn’t judge you for letting her watch it, at home. I understand you want to see it too, just I doubt she will sit quietly the entire time. As a fellow movie goer who loves fellow geeks, big and small, I wouldn’t like the disruption toddlers make in films.