Overnight, Teigen took to Instagram to share the first photo of her two children together, showing Luna handing Miles a dummy.
The adorable photo, captioned simply "❤️", is only the second time the little boy has been featured on social media.
"Hello, world! This is Miles Theodore Stephens," Teigen shared on May 21st.
"We are drowning in his little peeps and nuzzles. Our household feels overwhelmed with love. Thank you for all your well wishes!"
Before Miles' arrival, new father-of-two, Legend, said he thought 2-year-old Luna wasn't ready to be a big sister yet.
"Luna’s gonna be an issue. I think she’ll probably have some growing pains because she’s currently running the house right now," the musician said at the Tribeca Film Festival.
"She’s used to being the centre of everything right now, so we’ll see how she adjusts to sharing the spotlight."