Factual error: The Douglas firs or Redwoods shown at the front of Longbourn (Groombridge Place) were not introduced to the UK before 1827, but the film is set in 1797.
Other mistake: When Darcy proposes to Lizzie notice the clock on the mantle does not change time. Nor does the clock change time when the Bennetts are discussing having the militia leave town.
Answer: According to the book, at the beginning, Jane 22, Elizabeth 20, Mary between Elizabeth and Kitty so 18 or 19, Kitty 17, Lydia 15.
Myridon