Who is Luna Lovegood in Harry Potter and the Half-Blood Prince?

[Steven]

Luna Lovegood is a Ravenclaw student one year younger than Harry. She is described as having straggly, waist-length blonde hair and a "permanently surprised look". Her father is Xenophilius Lovegood, the editor-in-chief of The Quibbler. Her mother died when an experiment went wrong. Luna witnessed the death of her mother when she was only nine and thus she is able to see Thestrals. Luna is isolated at school, but she appears to care little for what others think.

In Order of the Phoenix, she and her father are among the few who believe Harry and Dumbledore when they claim that Voldemort has returned. Luna also becomes a member of Dumbledore's Army, and later in the book joins Harry, Ron, Hermione, Ginny, and Neville in the conflict with Death Eaters at the Department of Mysteries. In Half-Blood Prince, after Luna and Neville are snubbed by some of Harry's new fans, she observes that people expect him to be with "cooler" people. Harry states that she and Neville are cool, which cheers her up. At Christmas, Harry invites Luna to go to the party hosted by Horace Slughorn. She also does the Quidditch commentary for Gryffindor's game against Hufflepuff, a scene that Rowling really enjoyed writing and which she considered "blinding insight". Later, when Death Eaters attack Hogwarts, Luna, Ginny and Neville are the sole D.A. members who answer the call to protect the school.