Does it have to be a Pride and Prejudice retelling? Or can it be a book with similar key aspects? I've heard good things about "Shades of Milk and Honey".
Jane resists this fate, and rightly so: while her skill with glamour is remarkable, it is her sister who is fair of face, and therefore wins the lion’s share of the attention. At the ripe old age of twenty-eight, Jane has resigned herself to being invisible forever. But when her family’s honor is threatened, she finds that she must push her skills to the limit in order to set things right–and, in the process, accidentally wanders into a love story of her own...http://www.maryrobinettekowal.com/novel/shades-of-milk-and-honey/
btw, I love Pride and Prejudice as well. Have you checked out the Lizzie Bennet Diaries on YT? www.youtube.com/watch?v=KisuGP2lcPs