Was wondering how to officially tell if she is or not.
There are several different signs that a hen might be broody. I've had hens that displayed most of them and never truly went broody. Some do that for a couple of weeks before they decide if they are going to go full blown broody or not. My test to determine if she deserves hatching eggs is that she has to spend two consecutive nights on the nest instead of sleeping in her normal spot. Not one night, not every other night, but two consecutive nights. That test may fail me some day but it hasn't yet.
I agree with Aart that the behaviors you describe are "normal", at least as normal as anything to do with chickens can be. I once had a hen that took three hours on the nest to lay her egg. Much longer than the others. She was also a nest hog, she would not let any other hen hop in the nest with her to lay. It's not that unusual for me to see three hens piled in one nest laying together so her nest hog behavior was different.
You never know when a hen will go broody but what you describe does not seem to me that she is even close. Each chicken has its own personality, that's what makes Chicken TV better than anything on satellite, cable, or network. She's just showing her personality.