Pattie Mallette shared a sweet selfie of herself with the 21-year-old model on Instagram.
"What a gift!" the "Sorry" hitmaker's mum captioned the shot, adding a heart-eyed emoji. In the snap, Hailey can be seen planting a kiss on Pattie's cheek.
"Love you," the model adorably commented on the post.
The Canadian star, 24, reportedly wed Hailey - daughter of actor Stephen Baldwin - at a New York City courthouse in September (18).
The couple had got engaged back in July after a whirlwind romance.
Although Justin and Hailey tied the knot a few months ago, they plan on having an intimate ceremony - followed by a huge bash - for close friends and family to celebrate their nuptials.
"They've been figuring out the perfect time to do it, and they both feel like the sooner, the better," a source told People. "They're still figuring it out."
The sweethearts originally planned a bash this month, but are now pushing it back to February, according to the New York Post's Page Six.
Justin and Hailey have reportedly already sent out 'Save the Date' cards to guests for 28 February, and the singer's personal DJ, Tay James, has been recruited to spin tunes during the party.
One family member is sure to be pleased with the news, as Hailey's uncle, actor Billy Baldwin, previously encouraged the pair to "take care of both families" by throwing an official celebration.
He also praised the new addition to the Baldwin family, and gushed: "I had a chance to have lunch with him (Bieber) recently... and it was nice to get a real hit of him."
"He's a very cool guy and super talented and he's got a huge heart - and they're madly in love," he added.