help: how to make the holes in african flowers smaller

i'm trying my hand at an african flower horse but i find i have big holes where you put 4 or 7 stitches into the one chain space. is there a trick to make these holes smaller? i've tried using a hook a few sizes down but they're still pretty big and you'll be able to see some stuffing

does everyone just not worry about the little bit of stuffing showing through or am i missing something?

thanks for the help