Disclaimer: I do not own any of the Characters nor the Works of Harry Potter. May contain spoilers
Fleur and Gabrielle's Parents name weren't mentioned in the book, Parents name are made up. Notice that Gabrielle is the youngest sister.
Caitlin Delacour is specified as a half-blood (see blood purity). She is quarter Veela and half witch mother and a wizard as a father. Caitlin's mother attended Beauxbatons Academy while Caitlin's father attended Hogwarts. Caitlin's mother's name is Catherine and Caitlin's father's name was James. James currently works in the Ministry of Magic as a Junior Secretary. Catherine doesn't work at all, mainly does the housework and write letters to other relatives.
Caitlin was sent to James's grandparents in 1981 since taking care of one teenage girl was hard and they mainly use a lot of money when Fleur was attending Beauxbatons Academy (Who said supplies was free?). In 1986, Gabrielle, the youngest sister in the family was born, and was kept in the family since it wasn't difficult to rise. Caitlin lived with pure-blood grandparents who are similar to the Weasleys. James's grandparents respected non pure-bloods and muggles (non-magical folk). Caitlin discovered that she was quarter Veela at 8 years old when she looks at herself in the mirror. She has immense beauty.
Caitlin visits her sisters in France every summer to socialize and do activities with them. Caitlin is the only one of the siblings that can speak English fully. Gabrielle knows most of the English Language, but not all of it. Fleur only knows some English and when she talks, she use broken English.
Caitlin has beauty, but she has more courage and strength than Fleur and Gabrielle have put together. She is brave and don't let anything get in her way. For example, she punches Draco Malfoy after she was insulted. She is also smart, and able to do assignments perfectly.
Caitlin has some weaknesses. Some boys like Ron, is attracted by her Veela appearances. Caitlin frequently gets love letters from Ron, Fred, George, and other male students. She can't decide which one will become her boyfriend. It becomes a problem when she has to pick someone for the Yule Ball in 3rd year (which won't be coming for awhile). Also, when she gets insulted, she will cry or weep for hours. She cares about her reputation and also, her appearances. As most teenager witches notice, being fat is not good when you want to be beautiful. Caitlin would eat a lot of fruits, vegetables and some meat, but hardly touch the beef.
Caitlin has a beautiful appearance. She has a beautiful face, shinny, straight long blond hair, and blue eyes. She usually wears a beautiful dress during a party. When she is at home, she wears a skirt and a sweater. She cares about her appearance so much that she even uses makeup. Most students at Hogwarts don't use makeup normally, but Caitlin seems to use it every day to maintain her beauty.
How is Caitlin like? Caitlin is a nice, sweet, smart girl. She is outgoing that she needs to talk all the time. Caitlin likes to draw pictures, and make stories about the wizarding world and magical romance stories in the Wizarding Community. She is especially fond with nature. She likes to explore the outdoors to learn more about the environment.