Baby Talk?

I've never been one for baby talk. Every time I hear a Mom talking that way to their child I cringe. I've tried to make a conscious effort to always speak to the girls as I would an adult. I've never really used simpler words in exchange for more complex ones. The other night, the girls were playing one of their favorite games, which is building a fort in the living room, creating a tunnel between the couch and the ottoman. Kira said something that caught me off guard. 'Maia, I'm quite nervous about travelling through the tunnel'. While this is a perfectly fine sentence for an adult, when it comes out of the mouth of a 4 year old, you have a tendency to stop and wonder...have I gone too far with the adult language? Am I somehow making them grow up faster than they should? I decided to listen for the next few minutes to see if this was just a fluke. Some examples I heard are, 'Wow, that was wonderful', and 'Maia, I am so proud of you. I love you so much.'. I decided that having a decent vocabulary at that age isn't the worst thing in the world.