John Mulaney's Wife Olivia Munn Lays Bare Motherhood Battle After Having Second Baby Following Brutal Cancer Fight: 'It's Not for the Faint of Heart'

Olivia Munn is brutally honest about the realities of being a mother to two young children, RadarOnline.com has learned.

After the 44-year-old welcomed her second baby with her husband, John Mulaney, via surrogate and endured a brutal battle with cancer, Munn took to her Instagram Stories to give her followers a glimpse inside her life as a parent.

"Having a toddler and a newborn at the same time is not for the faint of heart," she wrote in the Saturday, October 12, social media update about taking care of her 3-week-old daughter, Méi, and son, Malcolm, 2.

In an additional post, Munn asked her followers, "Why do newborns always stay awake?" The brunette star then shared the results of her Google search which read, "Newborns often stay awake at night because they don't have established sleep-wake rhythms" and that they "don't understand the difference between day and night."

"Hope everyone's having a great night," she sarcastically captioned the photo of the internet's answer.

The Hollywood power couple, who tied the knot in July 2024, welcomed their little girl into the world on September 14. "I had so many profound emotions about not being able to carry my daughter," Munn penned in the announcement shared to Instagram of their baby's birth.

"When I first met our gestational surrogate we spoke mother to mother. She showed me so much grace and understanding, I knew I had found a real-life angel. Words cannot express my gratitude that she kept our baby safe for nine months and made our dreams come true," she gushed. "I am so proud of my little plum, my little dragon for making the journey to be with us. My heart has exploded."

The happy update comes months after Munn revealed she was diagnosed with b----- cancer earlier this year and underwent a double mastectomy. "I wouldn’t have found my cancer for another year — at my next scheduled mammogram — except that my OBGYN, Dr. Thaïs Aliabadi, decided to calculate my B----- Cancer Risk Assessment Score. The fact that she did saved my life," she penned in a March 2024 post.

"Dr. Alibadi looked at factors like my age, familial b---- cancer history, and the fact that I had my first child after the age of 30. She discovered my lifetime risk was at 37 percent. Because of thats score I was sent to get an MRI, which led to an ultrasound, which led to a biopsy. The biopsy showed I had Luminal B cancer in both b-----. Luminal B is an aggressive, fast moving cancer," The Newsroom actress added.

Besides the utter shock of her diagnosis, Munn's biggest fear was the possibility of not being there for her kids. "I was not someone who obsessed over death or was afraid of it in any way but having a little baby at home made everything much more terrifying," she explained in a recent interview.