Here's how I know:
1. Change of Name: I am no longer "Mommy," "Mama," or even "Mom." I am "Mother." As in, "Mother, could you please tell Dexy not to disturb me while I am playing with my ponies?" Additionally, Sven has become "Father." She feels it's more sophisticated.
2. Big words: Princess has decided that she has to use the hardest word she knows for everything. Unfortunately, in the way of four-year-olds, she has decided that the existence of a harder word negates the existence of an easy one. Hence the following conversation:
Me: Princess, you can be quiet and let your brother sleep, or you can go downstairs. Those are your choices.
Princess: Mother, those aren't choices. You don't give me any choices.
Me: Princess, I just gave you two choices: be quiet or go downstairs.
3. Teacher: Princess is now smarter than anyone else in our family, and most people not in our family. She demonstrates her intelligence by teaching everyone else. I hope it is to my credit that "teaching" to her means "giving a lot of verbal praise and encouragement." Yesterday, I saw Princess teach a mother cat how to nurse. It went like this:
Princess: Okay, Mama Cat, your kittens are right here. Lie down and let them crawl over to you. That's it, very good. Oh, very good! Now they're all getting a drink. Okay, now this one's finished, so I'm going to take her and go play. Is that all right? (Cat meows) Thank you, Mama Cat.
Then, as Princess walked by me with the tiny kitten in her arms, I heard her say, "Kitten, I like your attitude."
Don't we all.