Board Thread:Speculation House/@comment-4830106-20140808001942/@comment-24993958-20140809212920

I think we need to look at Penny both in universe and real life.

In universe, Grimm are defined by their lack of aura; it's something they can’t have because, as stated, they lack a soul

In real life, Penny is inspired by Pinocchio, a boy that started as a doll and ended as a human, because he learned how to be one. In other words, he gained a soul.

I think it’s reasonable to predict Penny will gain an aura, aka a soul, at the end of her character arc.