Jessica Simpson and Eric Johnson's kids Maxwell, 2, and Ace, 13 months, played significant roles in the couple's wedding on Saturday, July 5, a source confirms to Us Weekly Credit: Jamie McCarthy/Getty Images for Jessica Simpson Collection

Picture perfect!

Jessica Simpson and Eric Johnson invited more than 250 guests to their lavish wedding ceremony on Saturday, but two in particular stole the show—Maxwell and Ace! A source confirms to Us Weekly that the couple's children didn't only dress for the occasion, they also took part in the ceremony.

Daughter Maxwell, 2, walked down the aisle as a flower girl, the insider reveals to Us. She was accompanied by her cousin, Ashlee Simpson's 5-year-old son Bronx. The bride and groom's 13-month-son Ace, for his part, served as ring bearer for his famous parents' special day. (The newlyweds postponed their wedding twice during Simpson's two pregnancies.)

According to a second source, many women at the bash donned floor-length dresses to the nuptials. Last month, Ashlee told Us her bridesmaid dress was "really beautiful" while attending the E3 Convention in L.A.

The 33-year-old blushing bride—who wore a custom Carolina Herrera gown—and the former NFL player, 34, were feted by boldfaced names like CaCee Cobb and husband Donald Faison, Jessica Alba and beau Cash Warren and Topher Grace as they exchanged vows. During the ceremony, they also chose to play an instrumental version of Chris Isaak's "Wicked Game."