"Seeing double.... #thisisus," she captioned the pic, which includes herself and Milo Ventimiglia with 9-year-old versions of Kevin, Kate, and Randall, played by Parker Bates, Lonnie Chavis and Mackenzie Hancsicsak, respectively, as well as their teenage counterparts, played by Logan Shroyer, Niles Fitch and Hannah Zeile.
While the snap is too cute, we couldn't help but wish that the adult versions of The Big Three, played by Justin Hartley, Sterling K. Brown and Chrissy Metz were there to complete the Pearson family photo. We weren't the only ones!
"Missing the bookends of @sterlingkb1 @justinhartley @ChrissyMetz & the babies then it'd be the complete Pearson family @TheMandyMoore!!" Ventimiglia wrote back.
We cannot get enough of the adorable Pearson family on This Is Us -- Ventimiglia's character, Jack, included!
ET caught up with the actor at GQ's Men of the Year event in Hollywood on Thursday night, where he promised that it'll be a while before we say goodbye to Jack for good.
"I think it's going to be a ways off," he said. "You're going to forget about it, you're going to get wrapped up in the lives of Jack and Rebecca and The Big Three, and then when you've forgotten that he's gone, we're going to hit you with it and it's going to crush you."