Justin Bieber’s mom is celebrating her son’s growing family amid the birth of his first child, Jack Blues Bieber.

Shortly after the Grammy winner, 30, announced the birth of his first son with model-entrepreneur wife Hailey on Friday, Aug. 23, Bieber’s mother and author Pattie Mallette shared her excited reaction on her Instagram Stories — where she called the arrival of the newborn a “miracle.”

“OH MY HEART,” Mallette, 49, wrote in all caps above Justin’s image of the baby’s foot. “WELCOME BABY JACK!! I LOVE YOU SO MUCH!.”

“THANK THE LORD[,] WHAT A MIRACLE! ,” she added over the photo itself.

Justin is Mallette’s only son, so the birth of Jack marks her first experience as a grandmother. Justin also has three half-sisters and one half-brothers through his dad Jeremy Bieber.

On Saturday, Aug. 24, Jeremy, 49, shared his own post on X. “Papa,” he wrote, apparently alluding to his son’s status as a dad now.

Justin confirmed the baby news on Friday, Aug. 23 when he shared a snap of the child’s foot to Instagram, captioned with “WELCOME HOME JACK BLUES BIEBER.”

Hailey, 27, shared her husband’s post on her Instagram Stories, adding their son’s name and a teddy bear and blue heart emoji.

The longtime couple first announced they were expecting their first child together in May 2024 on Instagram, with a rep for Hailey telling PEOPLE that the Rhode founder was over six months pregnant at the time.

The pair wed in September 2018 in a New York City courthouse, just two months after their engagement, before having a larger ceremony in South Carolina the following year.

Mallette has already been supportive of Justin and Hailey during their parenthood journey, as she shared a heartfelt message dedicated to her son on Father’s Day back in June. The Instagram post, which came one month after the pregnancy announcement, featured a handful of snaps including some of Justin and Hailey. “Happy Father’s Day, Justin,” Mallette began her caption.

“You’ve always wanted to be a dad ever since I can remember,” Mallette added. “You have so much love to give. You’re gonna be the best daddy ever. You already are. LOVE YOU!! ”

She later wrote on her Instagram Stories that she was “soooo excited” for her son.

Other relatives in the Baldwin and Bieber families have showed some love to the couple after the birth of baby Jack. Among them, Hailey’s dad Stephen Baldwin shared Mallette’s tweet, adding his own message: “Amen, Congratulations to you and may God continue to bless our family.”

Celebrities including Tori Kelly, Ice Spice, The Kid LAROI, Tems, Coi Leray and Chance the Rapper also sent wishes — and left comments — under Justin’s post.