The Rhode founder and model, 27, and her musician husband, 30, announced they are expecting their first baby together on Thursday, May 9, via Instagram.

Justin’s mom, Pattie Mallette, shared an Instagram Reel following their announcement expressing her excitement. “So I have been waiting for this day. And now that they have shared it, I can finally celebrate with y’all, and oh my gosh, I’m gonna be a grandma,” Mallette, 49, said.

“Okay, Justin and Hailey you are going to be the best parents ever. And I am so excited. Oh my goodness, praise God,” she concluded.

“BABY BIEBER IS ON THE WAY!! I’m gonna be GRANDMA!! 🎉🙌. CONGRATULATIONS @justinbieber and @haileybieber !! My heart is so full. What an exciting new adventure. Love you so much,” she wrote in the caption.

Along with the singer’s mother, his stepmom Chelsey Bieber — who married his dad, Jeremy Bieber, in February 2018 — expressed her excitement in the comment section of his post, simply writing, “❤️❤️❤️.”

“LOVE U GUYS❤️❤️,” added the Grammy winner’s step-sister Allie Bieber, with his half-sister Jazymn commenting on Hailey’s post: “❤️🩷🩷.”

“baby glazed 🍩,” Hailey’s cousin, Ireland Baldwin, joked in her comment section.

Following the couple’s announcement, a source told PEOPLE that the day the parents-to-be found out they were expecting their first baby together was “just the best day for them.”

“Everyone is excited for them,” the source said. “They will be great parents, and Justin will be super involved. This will be the next important project for him. He’s so excited to raise his baby.”

“They have a name that they think is perfect. They’re also starting to decorate a nursery. They can’t wait to meet the baby,” the insider added.

“They have both been very emotional about it. They feel so blessed,” said the source. “They’ve also felt very protective of the baby from the moment they found out. They shared with family and close friends early on. It was very important for them to keep it quiet and just enjoy [it] for as long as possible before they publicly confirmed.”

Justin and Hailey’s announcement included a video showing the couple, who have been married since 2018, renewing their vows.

The Rhode founder wore a Saint Laurent by Anthony Vaccarello white lace dress that showed off her growing baby bump. She paired the look with a custom, floor-length design with a bespoke lace head scarf, a headpiece that doubled as a veil, and black Saint Laurent sunglasses.