Yes, they do!Do normal sized cochins count? I have 3 normal cochins. But they seem to grow so slow. They need to grow a bit more than double their size, and they are ~7 months old
It's normal for cochins to develop slowely, but being so small at 7 months? That's weird. Are you sure they're not bantams?

Cochins really do grow slowly! Your Cochins are very cute! My Ms. Frizzle actually looks smaller after losing a bunch on her juvenile feathers. She’s getting rounder too!