Alexa Ray Joel, Sailor Brinkley-Cook dish on mom Christie Brinkley

Singer Alexa Ray Joel and model Sailor Brinkley-Cook, the daughters of Bridgehampton supermodel Christie Brinkley, recently joined their famous mother in a fashion shoot and talked about what aspects of her might surprise fans.

"I think something that people would be surprised about my mom is that she's very chill. It's not always glam," said Brinkley-Cook, 22, in the video portion of an "Entertainment Tonight" article on that entertainment-news program's website Friday. "With supermodels," Brinkley-Cook explained in the text portion, "you think that they're constantly stressed about how they look, and I think with my mom, it just comes really naturally to her. Like if she feels good, she's gonna look good. She focuses on feeling good, which is definitely important."

Brinkley-Cook said her mother, 67, "has a very bubbly, energetic personality, but she takes her time in the morning. She doesn't need to, like, get on a face of makeup and full outfit. … She can chill in her pajamas, do work, emails, play with the dog and then put on some overalls and go to the garden all day."

Joel, 35 — daughter of Brinkley and Long Island-raised Rock & Roll Hall of Famer Billy Joel, Brinkley's second husband — added enthusiastically, "She's an incredible painter! … She actually painted my father, Billy Joel's, [1993] 'River of Dreams’ album" cover. Brinkley's eldest child, who called the painting "gorgeous," added: "A lot of times I've put that up [online], and people will be, like, 'Who painted that?' and I'm, like, 'My mom!' "

Brinkley-Cook — whose father is architect Peter Cook, Brinkley's fourth husband — also noted in the video that while her mother is part-owner of the prosecco brand Bellissima, the iconic supermodel is not much of a drinker, and when tipsy sends her youngest child "less of, like, a drunk text … but more of, like, a drunk Instagram Story or something. Like … a really funny video."

"Oh, yeah, that's true," interjected Joel. "And she gets extra giggly."

"And be like," Brinkley-Cook responded, launching into a sing-songy voice, ''I just drank my Bellissima — and I feel amazing!"

Brinkley, good-natured throughout the interview, noted in the video that the shoot for NYDJ jeans marked "my first time back on the set since I had my hip replaced, and I feel like, 'Oh! Yeah, I can swivel again. I can move.' "

"My Theatrical and Opinionated Daughters … Lol! I love my babies," she additionally wrote on Instagram, where she also acknowledged Jack Brinkley-Cook, 25, her son with third husband Ricky Taubman. Peter Cook later adopted Jack.