But it isn't a true Blue Smith unless it has a very unique name, so meet Gravity Blue Smith.
18-year-old Lucky took to Instagram to announce the arrival, with an adorable photo, and even more adorable caption: "She's here😍😍😍 meet Gravity Blue Smith, I've never felt so happy... I love you more than anything in this whole world little princess."
26-year-old Stormi also shared a pic a few minutes later.
"Welcome to the world little angel, the most perfect beautiful gift I could have ever dreamed of little miss Gravity Blue Smith."
Congrats to them!