VIDEO : Chrissy Teigen and John Legend Celebrates Luna's 4-Month Birthday

Happy birthday, baby Luna Simone Stephens! Well, sort of. This weekend, Chrissy Teigen and John Legend's daughter turned 4 months old, and her parents took to social media to celebrate her milestone. "I now celebrate monthly birthdays I guess," Chrissy wrote over an adorable video of her baby girl cooing. She also added an adorable caption to the video, "4 months.