“Too big for her britches” is perfect. Similar to fair weather fan, my general go to move when that happens is putting my dog on her back and staring into her eyes. 5 seconds of struggling from that position and she’s submissive again. She usually walks away looking sad and then comes back to me and licks my hand. My friends think that I’m really strange, but it’s a very similar move to what “mother dog” does when her pups get out of line.
Another tip is to never lose a “physical game” with your dog: Tug of war with a sock, etc. I usually give her a fighting chance amd then pull it hard for the win. Never let your dog enter a room before you. Never let your dog get on top of you. Never sleep on a lower surface than your dog. If the dog sleeps on your bed (I don’t recommend it, make sure it’s at the foot). I know that it sounds like harsh and people love their dogs, but I’m telling you they look for signs of weakness to takeover your spot in the pack. The more you let the dog think it’s more important than you, the more corrections you have to make. Also if the dog thinks that it is the head of the house pack, the dog will challenge humans elsewhere in public.
I always watch in amazement as I see dogs walking their humans - pulling their leash, especially if it’s a big dog. I don’t go anywhere near those animals as they are dangerous.