Olivia Munn has compared the pressures of being a mother to landing on Mars.

The 44-year-old actress, known for her role in 'The Babymakers', spoke candidly with host Jenna Bush Hager on 'Today with Jenna and Friends' about how drastically her life has changed since welcoming her second child, daughter Méi, with her comedian husband John Mulaney.

She said: "It is so much fun every single day.

"(But) it's like I just landed on Mars. This is insane. How does anyone do this?"

Olivia also revealed how the adjustments of motherhood led her to a moment of vulnerability.

She said: "We have the baby, who's born in September. John was on Broadway. He was rehearsing all day long and then doing his previews at night for two weeks and… my three-year-old was like hitting his limit."

The strain caused some tension at home, especially when her son Malcolm Hiệp, 3, began to express jealousy towards his new sister.

Olivia added: "It was like screaming and crying, and like saying things to where my feelings were getting hurt.

"I broke down crying - a cry I have never cried."

Despite the challenging moment, Olivia said about how it ultimately led to a powerful wake-up: "I was so distraught, but then this realisation, and I said, 'God willing, we get to work as much as we are working now forever, and God willing we're shifting and jumping around and moving everywhere, and we're so lucky'."

She also said her difficult family moments often ended with laughter, which make it easier for her to cope.

Olivia and John, 41, had their son Malcolm in November 2021.

The 'X-Men: Apocalypse' actress, who had a double mastectomy following a breast cancer diagnosis, carried Méi via surrogate.

Earlier this month, the actress posted a heartwarming moment on Instagram of her daughter standing on her own, as she proudly cheered: "Good job!"

In April 2023, Olivia was diagnosed with an aggressive form of breast cancer, despite a recent clean mammogram and negative genetic tests.

She underwent a double mastectomy and additional surgeries.

The actress has emphasised the importance of proactive health measures, stating to Time magazine: "I thought, 'Man, there's so many women out there just like me. They might have no idea. And it may be too late by the time they find out'."

Throughout her illness journey, Olivia advocated for breast cancer awareness, encouraging women to seek comprehensive screenings.