Luna Lovegood is the daughter of Xenophillius Lovegood, her mom died bcoz as luna says "She used to experiment, but one day her spell backfired; I was nine then" harry- "I-I'm sorry"
Luna- "Yes I do feel sad about that sometimes, but at least I have my dad" she has blond-ish kinda hair and she wears reddish earrings, she's a Ravenclaw, there's a small mention of her in Harry Potter and the goblet of fire where Amos Diggory says "The Lovegoods arrived 3 weeks ago" (this happens when Harry, Hermione and the Weasleys (excluding Molly, Charlie, Bill, Percy, they apparated, molly didn't come) meet Amos if you remember this scene when Cedric jumps from the tree and Arthur is like "This charming young lad must be Cedric" Luna is sometimes described as a weirdo, Prof. Black describes her as "The Lovegood oddity" Luna is even taken to Azkaban (so sorry if I spoiled it for you)