Nettie! So cute! I like it, although, as I do with many of these names (like Lily, Charlie, Sally, Ellie, Abby, etc), I see it more as a nickname than a full name. I mean, if you want to nickname your daughter Nettie, you'd better give her a long name like Annette, Jeanette, Janet, Marilene, Marlene, Magdalene, or even Anna. Thus her name grows with her as she ages.
Normally, I would think of this as an ugly old lady name. But it's been growing on me lately and it sounds cute to me. Even so, I wouldn't name my child this.