"They were very down to earth and friendly," says an onlooker

By Melody Chiu
January 05, 2016 04:20 PM
Bruce Glikas/FilmMagic

Talk about a star-studded birthday celebration.

On Monday, Beyoncé, Jay Z and Solange celebrated Tina Knowles Lawson‘s birthday at Del Friscos Grille in Santa Monica, California.

Tucked inside the restaurant’s private dining room, the group feasted on steak, crab cakes, cheesesteak egg rolls and a selection of desserts while sipping on wine throughout the meal.

Dressed casually, Beyoncé and Jay Z “arrived around 8:30 and were holding hands,” an onlooker tells PEOPLE. “They were very down to earth and friendly, and everyone had a great time.”

Lawson shared photos from her birthday dinner on Instagram, showing her cuddling up to daughters Beyoncé and Solange as well as stepdaughter Bianca Lawson.

Last April, Lawson married her new husband Richard aboard a yacht in Newport Beach, California, surrounded by her loved ones.

“It couldn’t have been more perfect,” Lawson told PEOPLE.

She added: “To walk down the aisle and see all my friends and family and to see my handsome man standin’ there, and to know that at 61 you can still find love and have a magical day like that it was really beautiful.”