Alec, 55, and Hilaria, 29, have named the baby Carmen Gabriela Baldwin.
The actor’s 17-year-old daughter Ireland took to her Tumblr account to post a letter to her sister.
Ireland writes: “Dear Carmen, You have entered the world! Welcome! We have all been anticipating your arrival! By we, I mean a lot of people. Girl, you haven’t even met them, but there are a ton of people who care about you. I’m not sure where exactly to begin. There are so many things I want to tell you, though it is best that you discover those truths on your own.”
She continues, “ENJOY YOUR CHILD HOOD AND YOUR TEENAGE YEARS!!!! I grew up way too fast. I always hung out with an older crowd. I always wanted to do what the big kids were doing. I always wanted to date older boys. It is ok to have older friends. That’s not the point.
“The point is, act your age, not your area code. If you’re 11, be 11. If you’re 16, BE 16. Love it. I am currently 17 years old and I am worrying about things that I have no clue why I am even worrying about them! One of these days, you will own your own home and pay all these lame bills. Enjoy not having to pay bills. Seriously.”