I like the sheep very much. Modern looking. It does need to be outlined so you can differentiate between the white parts of the sheep and the ground and sky. I think that's why some people think it's alien looking.
I too would do flowers instead of ladybugs. I believe if you choose the right thread colors to quilt with you can really define sky and ground. I wouldn't worry about quilting grass in. I would just make sure the whole ground area is quilted with the green thread.
Its rs going to be a great quilt. Not necessarily what you or I would choose but your friend will like it.