A source confirmed to PEOPLE on Monday that Michelle Williams is engaged to Thomas Kail and the two are expecting their first child together

Michelle Williams is one striking mom-to-be!

The actress, 39, shone at the 2020 Golden Globe Awards on Sunday night, keeping her baby bump under wraps in a one-shoulder peach-colored Louis Vuitton gown (which took 156 hours to create from start-to-finish!) as she walked the red carpet alongside fiancé Thomas Kail. The silk crepe design, inspired by the label’s Spring-Summer 2020 collection, also features an asymmetric and draped body with knotted details across the shoulders and a draped, cinched waistband. The Hamilton director, 42, looked dashing in a traditional suit.

Also on hand to support Williams was her best friend and fellow Dawson’s Creek alum, Busy Philipps. The former Cougar Town actress, 40, looked stunning in a maroon sequin spaghetti-strap dress and matching heels.

Sunday’s glam event (where Williams is nominated for best actress in a miniseries or television film category, for her performance in Fosse/Verdon) marks the actress’s first event since her pregnancy news. On Monday, PEOPLE confirmed she is engaged to Kail and the two are expecting their first child together.

The four-time Oscar nominee is also mom to 14-year-old daughter Matilda, her only child from her previous relationship with Heath Ledger, who died in 2008.

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NBC's "77th Annual Golden Globe Awards
Michelle Williams (L) and Thomas Kail
| Credit: Todd Williamson/NBC/Getty
Busy Philipps
Busy Philipps
| Credit: Jon Kopaloff/Getty Images

The actress and Kail (who directed Williams in Fosse/Verdon, which is also up for best miniseries or television film) went public with their relationship when they were photographed together in London, where she has been busy filming Venom 2.

Williams was spotted buying baby clothes at Seraphine maternity boutique in Kensington — and as a source told PEOPLE this week, Matilda even played matchmaker for her mom and Kail.

Thomas Kail, Michelle Williams
Thomas Kail (L) and Michelle Williams
| Credit: Pip Hurley

Williams took home the award for outstanding actress in a limited series or a movie at the 2019 Emmy Awards in September (where she was also accompanied by Philipps) for her portrayal of Broadway dancer Gwen Verdon in Fosse/Verdon, and used her acceptance speech to stand up for equal pay.

“Thank you so much to FX and Fox 21 Studios for supporting me completely and paying me equally because they understood that when you put value into a person, it empowers that person to get in touch with their own inherent value,” Williams said at the ceremony. “And then where do they put that value? They put it into her work.”

“So the next time a woman, and especially a woman of color, because she stands to make 52 cents on the dollar compared to her white male counterpart, tells you what she needs in order to do her job, listen to her, believe her,” she added. “Because one day she might stand in front of you and say thank you for allowing her to succeed because of her workplace environment and not in spite of it.”

The 77th Annual Golden Globe Awards ceremony is airing live on NBC from the Beverly Hilton in Los Angeles on Sunday, Jan. 5.