Michelle Williams has welcomed her fourth child – and third – with husband Thomas Kail, per People.

The actress, 44, who has been wed to Kail since 2020, is said to have welcomed her new child via surrogate six weeks ago.

A source said: ‘They couldn’t be happier to expand their family, and Matilda has been doting on her younger siblings.’

The new family of six has been spotted around their New York neighborhood.

DailyMail.com has contacted Williams’ representatives for comment.

Williams is mom to daughter Matilda, 19, whose father is the late Heath Ledger who tragically passed away in 2008.

Michelle Williams has welcomed her fourth child and third with husband Thomas Kail

They have son Hart, four, who they welcomed in June 2020 and another baby who joined the family in 2022; the family are seen out in New York City back in October 2022

Michelle and Thomas got engaged in 2019 after working together on Fosse/Verdon and got married in March 2020.

They have son Hart, four, who they welcomed in June 2020 and another baby who joined the family in 2022.

Michelle also has daughter Matilda Ledger, 18, from her relationship with the late actor Heath Ledger, who died in 2008 at age 28.

The happy news comes hours after Michelle enjoyed a date night with her husband Thomas at the New York premiere of her steamy s3x drama, Dying For s3x, on Wednesday.

The Dawson’s Creek star made a bold fashion statement in a revealing lilac gown with cut-out sides as she posed with the theatre director, 48, at the SVA Theatre.

The pair — who have been married since 2020 — got flirty as they held hands, rubbed noses together, and gazed into each other’s eyes on the red carpet.

Her platinum blonde tresses were swept to the side and styled in a sleek bob, with delicate makeup accentuating her features.

The beauty — who shares daughter Matilda, 19, with the late actor Heath Ledger — accessorized with silver bangle bracelets.

The happy news comes hours after Michelle enjoyed a date night with her husband Thomas at the New York premiere of her steamy s3x drama, Dying For s3x, on Wednesday

The pair — who have been married since 2020 — got flirty as they held hands, rubbed noses together, and gazed into each other’s eyes on the red carpet

The dress had sizzling cut-out sides

Her platinum blonde tresses were swept to the side and styled in a sleek bob, with delicate makeup accentuating her features

Based on the hit Wondery podcast of the same name, the forthcoming s3x-positive FX series tells the story of Molly (Williams), a woman diagnosed with metastatic breast cancer who leaves her husband of 15 years (Jay Duplass) and begins to explore her s3xuality, according to Deadline.

Also present at the premiere was her pal Busy Philipps, 45, who looked chic in a black mini dress.

Michelle also posed with co-stars Rob Delaney, Jay Duplass and Jenny Slate, as well as creators Elizabeth Meriwether, Kim Rosenstock

Michelle has been busy promoting the new show in recent days.

‘The show careened from dramatic to absurd to hilarious to unbelievable and then back again,’ Williams described in a New York Magazine cover story Monday.

She also made rare comments about her husband when discussing how her new show influenced her feelings on s3x.

Michelle explained: ‘That’s why s3x is an answer to death. Because it’s the ultimate feeling before we’re left without any.

‘I got to go home and see my husband!’

‘You’ve already done, like, four scenes, and then it’s five o’clock at night and you have to do six masturbation sequences with six sculpted, individuated orgasms, and you’re like, “Woo! Okay,”‘ she recounted.

The beauty — who shares daughter Matilda, 19, with the late actor Heath Ledger — accessorized with silver bangle bracelets

The actress showed off her flowing dress

She wore pink nail polish

The two looked very much in love

Her character Molly is encouraged to make a life-altering change by her best friend Nikki Boyer, played by Jenny Slate.

‘She was healing wounds on her deathbed,’ Nikki told The New York Post in 2020. ‘Her lifelong dream was to write a book and be a published author. She waited until the last few months of her life to do it. She was thinking the clearest she ever had in her life.’

Meriwether and Rosenstock also serve as showrunners and executive producers with Headland, Katherine Pope, Boyer, plus Jen Sargent, Marshall Lewy, Aaron Hart and Hernan Lopez.

Production began years ago and picked up momentum in spring 2023 before the SAG-AFTRA and WGA strikes put it on hold.

The show, which marks Michelle’s return to acting following a hiatus, is her first project since she shot The Fabelmans.

It also marks Williams’ return to FX, where she starred as Gwen Verdon in the limited series Fosse/Verdon (2019).

For a hotel masturbation scene, Michelle had to get creative, coming up with six different ways to climax.

The star held hands with pal Busy Philipps, 45, as she showed off her backless dress

Busy wowed in a black mini dress

She posed with co-stars Rob Delaney, Jay Duplass and Jenny Slate, as well as creators Elizabeth Meriwether, Kim Rosenstock

She added, ‘I just kept joking, like, “Just so you know, this is how Molly comes, not Michelle. This is not my come face.”‘

And she mused: ‘[The show] definitely opened my eyes in a way that was also like, “God, I’m such a dummy for not having realized this stuff sooner!”‘

Amid the press tour for Michelle’s new show, one of her closest pals, Busy, shared rare remarks about their friendship — including the ‘moments’ she felt they ‘might not recover from.’

They first crossed paths in the 1990s while filming the hit teen drama series Dawson’s Creek, and quickly became close pals.

For a hotel masturbation scene, Michelle had to get creative, coming up with six different ways to climax

Dying For s3x can be streamed on Hulu via FX in the US and on Disney+ internationally beginning Friday

‘We just know each other and get each other in such a deep, fundamental way at this point,’ Philipps told to Page Six on Saturday.

She added that both she and Williams have experienced ‘so many different moments in each other’s lives,’ from ‘wonderful ones’ to ones they thought they ‘might never, ever recover from.’

However, Busy gushed, ‘When you have a friend like that, you’re blessed. That’s all you can really ever hope for in this life.’

Dying For s3x can be streamed on Hulu via FX in the US and on Disney+ internationally beginning Friday.