A few remarks on Luna's character traits . . . I don't own the girl, but I do own my thoughts.
She is strange.
But not in the way that everyone thinks. She is friendless because no one is willing to accept the social danger that comes along with accepting her. No one will subscribe to her strange beliefs, or even condescend to befriend her despite them.
And yet, she does not discard them. She does not compromise her beliefs for the sake of being liked.
She is unusual not because of what she believes, but because she refuses to give it up.
She is strong.
She is lonely, lonelier than she'd ever admit. Being called "Loony" every day wears on her, and it hurts when all people do is tear her down or steal and hide her possessions. But if she cries herself to sleep at night because of her loneliness, the endless teasing, she never lets on, and she never gives up her hope for better things.
She is devoted.
There is a reason she stays strong: She loves her parents more than anything in the world, and doesn't want to disappoint them. She is loyal to the memory of her mother, the most outstanding woman she has ever known. She tries every day to live up to the values her mother taught her: kindness, determination, pure love, and courage. The memory of her mother keeps her going in the darkest times.
She is the ultimate "daddy's girl" as well. Her father passed on most of her unusual beliefs, and gives her the strength never to give them up. He reminds her not to be afraid of what people say, and he is the reason she has never compromised herself.
She loves them both more than anything. They are the most important thing in her life.
She is a Ravenclaw.
She's clever, yes, and does well in school, but that's not enough to make you a Ravenclaw. Her brilliance lies in the way she thinks and what she sees. Her eyes seem to be able to penetrate the fog of convention, and social norms, and all that is "acceptable," to see what's really there. She can read subtext, tell what people are not saying, and what they really are. She knows why you are lying when you are, and she knows what you really want to say.
She's a Ravenclaw because her mind is open. Why shouldn't Crumple-Horned Snorkacks exist? Why can't there be heliopaths and Wrackspurts? Just because you can't prove that something is real doesn't necessarily mean that you can prove that it isn't.
She is just.
She can see the line between right and wrong, and she believes in it. She makes sure always to stay on the right. When she does something, she makes sure there is a real, right reason why, or why not.
She believes that all things are equal. House-elves should have just as grand a burial as any human. Goblins are equal to us in every way. Just because not everyone can see thestrals does not mean that they are creatures to be scorned.
She has many quirks, many characteristics, which all define who she is. But one thing is always for sure.
She is extraordinary.