Daria is older. Quinn is Daria's younger sister.
At the start of the show, Daria was a tenth grader, 16, while Quinn was 14½.
Voiced by Wendy Hoopes, DariaWiki.org describes Quinn as a stereotypical self-absorbed teenage girl who is concerned mainly by clothing, shopping, and being popular.
Her interests beyond such trivial things are minimal save for getting into a "Party College" with her friends. Often, she seems unaware of basic facts that are not connected with looks or fashion. She has also become afraid and insecure when she thought her looks were not good enough.
Of interest, find out Which Daria Character Are You and What Your Favorite Daria Character Says About You.
Watch online and download Daria cartoon in high quality at http://kisscartoon.me/Cartoon/Daria.