Heming spent her 42nd birthday Thursday with Willis, 65, their daughters, Moore, 57, and other family and friends.
Heming and Willis have two daughters, Mabel, 8, and Evelyn, 6. Willis also has three daughters, Rumer, 31, Scout, 28, and Tallulah, 26, with Moore.
Heming shared a photo on Instagram of herself with Willis, Moore, Mabel, Evelyn, Rumer and other partygoers. The guests enjoyed cake while lounging outside on blankets and pillows.
"It really was a happy birthday for me," Heming captioned the post, adding a heart emoji.
Real Housewives of New York alum Kristen Taekman and model Eugenia Silva were among those to wish Heming a happy birthday in the comments.
"Happy birthday my beautiful @emmahemingwillis!!!" Silva wrote.
Heming, Willis, Moore and their respective children are self-isolating together in Sun Valley, Idaho, amid the coronavirus (COVID-19) pandemic. Heming and her daughters were initially waylaid but joined Willis, Moore and the group in May ahead of Evelyn's birthday.
Rumer shared a photo in May of Willis wearing his iconic orange jumpsuit from Armageddon.
Heming and Willis married in 2009. Willis and Moore were married from 1987 to 2000.