On Tuesday, the 32-year-old supermodel took to Twitter to celebrate her mom, Vilailuck Teigen, becoming an American citizen. Chrissy shared the happy news with a video of Vilailuck holding her 2-year-old granddaughter, Luna, while saying the Pledge of Allegiance.
Wearing a stylish black-and-white blazer in the video, Vilailuck -- who is from Thailand -- looks thrilled as she holds her eldest grandchild in her arms. For the ceremony, little Luna is sporting a darling dress with a Peter Pan collar, pigtails and black Mary Jane shoes while holding an American flag.
"YES MOM!! Congrats @pepperthai2!!" Chrissy wrote alongside the video.
John also took the time to congratulate his mother-in-law by retweeting his wife's message and writing one of his own. "@Pepperthai2 became a US citizen today! 100% on her test!" he bragged.
ET caught up with Chrissy -- who is also mom to her and Legend's 5-month-old son, Miles -- earlier this month where she dished on her relationship with her husband of five years.
"People see John as this perfect entity and all I want to do is be like, 'Yeah, but he does this! But he really is that fantastic, and amazing, and amazing for me because I'm a fireball," she confessed. "Like, I'm crazy and he knows how to deal with me when we fight. And he knows just the right thing to say to diffuse it. And I think that is the problem, it's that it's so frustrating because sometimes you just want to fight and sometimes you just want to yell at somebody and he's never that person."
"Some people wonder, 'Does [having kids] shake it up a lot?'" Chrissy added. "But it didn't for us because it just became us against the kids, which I love too."
Here's more of ET's sit-down with the mother of two: