(Courtesy of emmahemingwillis/Instagram.com)

Bruce Willis' youngest daughters are already bonding.

Their mother, Emma Heming-Willis, posted this adorable Instagram photo of the couple's new baby girl Evelyn with her 2-year-old big sister, Mabel.

The photo, which shows Mabel gently cradling her baby sister's head while the newborn gazes up at her, is captioned "The start of a beautiful friendship."

Bruce Willis and His Wife Emma Welcome a Daughter

It is the second picture that model Heming-Willis, 35, has shared since she and her 59-year-old Hollywood A-list husband welcomed their new baby girl on May 5.

Over the weekend, she posted a photo that showed her breastfeeding Evelyn. She captioned it, "Breakfast of Champions. Photo cred: B. Willis."

The "Die Hard" star is also dad to three adult daughters with his ex-wife Demi Moore.