Diane Keaton is sitting on Cloud 9 following her daughter Dexter White‘s wedding on Saturday, June 12. The Oscar-winning actress was “so proud” to watch her eldest child marry her husband, Jordan White, during their “perfect” ceremony, an insider exclusively tells Closer Weekly.

“Diane has always been very private about her kids, even now that they’re older, but she’s so proud of them,” the insider shares with Closer on Monday, June 14, noting the Annie Hall alum, 75, was especially grateful to stand by her daughter’s side. “Walking Dexie down the aisle was one [of] her lifetime highs.”

Courtesy of Dexter Keaton/Instagram

As the mother of the bride, Diane made sure the day was all about Dexter, 26. “Diane has never tried to overshadow her kids, even at the wedding. She may be quirky, that’s her, but she’s never a diva,” the source explains. “It was Dexie’s day and she was a beautiful bride. The wedding was perfect.”

Because the Something’s Gotta Give star “adores” Jordan, as well as “his family,” Diane is thrilled her daughter found the person she wants to be with. “Diane cried, of course,” the insider points out. “She just can’t believe how time flies by.”

The doting mom of two — who adopted Dexter in 1996 and son Duke Keaton, 21, in 2001 — has yet to publicly comment on her daughter’s nuptials, but Dexter confirmed she tied the knot on Instagram. One day after saying “I do” to her beau of two years, Dexter reposted tons of pics and videos from guests via her Instagram Stories.

Leading up to the big day, the University of Arizona alumni teased the couple’s nuptials on social media. Alongside photos with Jordan, Diane, her mother-in-law and others, Dexter gave a glimpse inside her bridal shower in May.

Scott Roth/Invision/AP/Shutterstock

“Showered with love by my family and friends!” she gushed in the caption. “I’m so thankful for everyone who made yesterday so special!”

A week later, Dexter joked she was enjoying her “last sail before the veil” during her bachelorette trip in Newport Beach, California. “Thank you babes for an amazing weekend!” the brunette beauty captioned several pics with her bridesmaids and pals in late May. “You are all awesome, gorgeous, wonderful and fun! I’m so lucky to have each and every one of you in my life. I love you all!”

Now that the wedding planning fun is over, Dexter and her love are enjoying a honeymoon in Waikiki, Hawaii, according to Instagram. “Dexie and Jordan make an adorable couple. Diane couldn’t be prouder,” the insider tells Closer, noting the Book Club actress is already thinking about the day they start their own family. “She’s not pressuring them, but now she wants them to give her grandchildren.”