"Breakfast of Champions. Photo cred: B. Willis," Heming-Willis, 35, wrote.
In the snapshot, the mom of two is holding baby Evelyn while breastfeeding. The little tyke is wrapped in a blanket, and only the side of her face and dark locks are seen.
Willis, 59, and the model's new addition joined big sister Mabel, 24 months, earlier this month. She weighed in at 8lbs, 10oz., and was said to be doing healthy and "doing beautifully" at the time. Days after the birth, Heming-Willis shared a snapshot of Willis and their eldest on her official page. "Feeling lucky, loved, and blessed. Sleep tight everyone xx," she wrote.
This is the fifth girl for the Die Hard actor. Willis also shares daughters Rumer, 25, Scout, 22, and Tallulah, 19, with ex-wife Demi Moore.