You know, I would look at Na Hoku, just to look. Some of my favorite pieces are from there. They are not really classic pieces, but I feel "blessed" when I wear them. (I grew up in a beach town, so that may have something to do with it.)
There is not a big following here on tpf, but I think a child might enjoy wearing some of the more realistic pieces. I'm especially fond of the rose gold and pink mop pieces.
The store has a bigger selection than their web site. I would go in person - I don't think I would order from them online because jewelry is so different in person.
For the child, I would choose a pendant over any other piece. That just seems more special to me.