Something subtle rather than truly owl-like might be nice--green metallic "pearls" perhaps.

i second this - I think it needs subtlenss. Metallic pearls would work or maybe embroider French pearls in a slightly different thread?

they are gorgeous btw - I am impressed!

Okay, so these are just adorable AND GORGEOUS. Seriously, the colors, the detailing, LOVE THEM.

So cute! I vote buttons on one owl.

That's a good thought. Maybe you don't want exactly the same eyes on both sweaters, even allowing for size difference.

Her dad says rainbow eyes on the little one, and lemon/lime on the big one.

I have no desire to sew buttons. :-/