Kim shared a photo of all 3 of the Kardashian family baby girls -- her daughter Chi on the left, Khloe's daughter True in the middle, and Kylie's daughter Stormi on the right -- sitting on a soft, fuzzy carpet together looking up at ... something that caught all their attention.

Kim captioned it "The Triplets" with heart emojis ... and also tagged her sisters in the pic.

If you're keeping track, Chicago is 8 months old ... True is 5 months ... and Stormi is 7 and a half. No word why Stormi's the only one wearing shoes.