Michelle Williams has publicly thanked her surrogate after she recently welcomed her fourth baby.

Earlier this year, it was reported that the 44-year-old actress and her husband, theatre director and TV producer Thomas Kail, had welcomed their third child - her fourth - via surrogacy.

During an appearance on Jimmy Kimmel Live! on Monday, Michelle expressed her gratitude to her surrogate, Christine. This came after guest host Tiffany Haddish told the actress that she looked as though she had never had children.

"Then I've got to give a big shout out to Christine, 'cause this last baby did not come through my body," the Dying for Sex actress said light-heartedly. "But the miracle of our little girl is thanks to Christine. Maybe you're watching out there; thank you, Christine."

She added, "Thanks to Christine, I have three under five at home."

This is the first time that Michelle has revealed any details about her surrogacy journey or confirmed the gender of her youngest child.

The Dawson's Creek star shares her eldest child, her 19-year-old daughter Matilda, with late actor Heath Ledger.

She then had her first child, named Hart, with Thomas in 2020, the same year they got married. The couple welcomed their second child in 2022, followed by their third earlier this year. The names of these two children have not been revealed.

Elsewhere in the interview, the mother of four admitted that she is still trying to achieve a work-life balance.

"Everything's good and under control. I'm the adult," she joked. "I'm trying to figure out the sort of life-work balance."

"I hear a lot of people are talking about self-care, and I'm just wondering when. Because I'm a working mom," Michelle continued. "Like, I already have the guilt, and I don't want to take more time away from them, but I understand, like, I need to fill up the tank."