Justin Bieber's Mom Pattie Mallette Reacts to Hailey's Pregnancy: 'I'm Gonna Be a Grandma!'

Justin Bieber's mom is overjoyed by the news that she's going to be a grandmother in just a few months.

After what had to be an impossibly long wait, Justin Bieber's mom, Pattie Mallette, can finally publicly celebrate her son's exciting baby news.

The 49-year-old grandparent-to-be took to Instagram on Thursday to celebrate the recently revealed news that Justin and his wife of nearly six years, Hailey Bieber, are expecting their first child together.

"So, I have been waiting for this day, and now that they have shared it, I can finally celebrate with y'all and say: Oh my gosh! I'm gonna be a grandma! Oh my goodness!" Pattie declared in a video she shared to the platform.

"Justin and Hailey, you are going to be the best parents ever," Pattie continued, before declaring, "I am so excited!"

"BABY BIEBER IS ON THE WAY!! I’m gonna be a GRANDMA!!🎉🙌CONGRATULATIONS @justinbieber and @haileybieber!!" Pattie captioned the post. "My heart is so full. What an exciting new adventure. Love you so much!"

A rep for the soon-to-be first-time mom confirmed to ET on Thursday that Hailey is "a little over six months pregnant."

After noticeably keeping a low profile in recent months, the 27-year-old model and her 30-year-old husband revealed the news on social media. Instead of words, the two posted photos and videos from their outdoor vow renewal ceremony in Hawaii, where Hailey's baby bump is on full display as she dons a white lace gown for the occasion.

"Hailey and Justin are thrilled to be expecting a baby together," a source told ET. "They have wanted this for a long time and can't wait to expand their family and bring a child into the world."

"Hailey and Justin are united and have been on the same page when it comes to parenthood," the source added. "They have experienced so much together as a couple and feel ready to take this next step in their lives and relationship. Hailey is such a natural caretaker and Justin knows she will be the best mom, and Hailey has always thought that Justin will make an amazing dad. Hailey, Justin, their families and loved ones are so excited for this beautiful blessing."

In 2019, Justin predicted how he would be as a father, writing in an Instagram post to Hailey, "One day I’ll be doing daddy daughter dates….. not hinting at anything soon I’m not in a rush. I just wanna enjoy you by yourself for a while!"