Best big sis from the get-go! Kim Kardashian recently shared the sweetest throwback photo of her children, Psalm and North West, on her Instagram feed on December 28 — and needless to say, the 6-year-old was taking her role as older sibling quite seriously. In the adorable picture, Northie held and fed her infant brother. So sweet.

“Flashback to when Psalm was so little,” the 39-year-old captioned the milestone photo. “My baby Northie is so helpful. How are my babies getting so big,” she concluded, adding a sobbing emoji. We get it, Kim — it seems like North, Psalm, Saint and Chicago have all really grown up in a flash.

We weren’t the only ones who fell in love with the photo, though. Kim’s fans and celeb friends flocked to the comments section to show love on the adorable image. Kylie Jenner‘s BFF Yris Palmer commented on the pic with a heart-eyed emoji, while a fan gushed, “She is so caring,” adding heart and clap emojis. “Sister duty!” another follower raved.

This isn’t the first time Northie has fawned over her youngest brother recently. In fact, the stylish Kar-Jenner kid posed for another photo with Psalm back on December 16, where she hugged the tiny tot while relaxing on the couch.

Just after Kim and her husband, Kanye West, welcomed Psalm back in May, an insider revealed to Life & Style exclusively that their eldest child wanted to be super involved with the newborn. “She’ll let North pick out onesies and other cute baby clothes for Psalm to wear so that she feels involved,” the source revealed. “So far there haven’t been any jealousy issues, North adores Psalm and treats him like a little doll.” Clearly, she still does!

Another insider gushed about what a good baby he is — and how much grandmomager Kris Jenner adores him. “He is such a sweet baby and always has the most calm, serene look on his face,” the source exclusively dished to LS. “He is a great baby and hardly cries, Kris is always calling him Sweet Psalm. Kris jokes her kids better give her another baby grandchild soon because she misses the little bitty babies around the house!”