Pride & Prejudice

During the late 18th century, the Bennet family, consisting of Mr. and Mrs. Bennet and their five daughtersâJane, Elizabeth, Mary, Kitty and Lydiaâlive in comparative financial independence as gentry at Longbourn, a working farm in rural England. As Longbourn is destined to be inherited by Mr. Bennet's cousin, Mr. Collins, Mrs. Bennet is anxious to marry off her five daughters before Mr. Bennet dies.
Wealthy bachelor Charles Bingley has recently moved into Netherfield, a large, nearby estate. He is introduced to local society at an assembly ball, along with his haughty sister Caroline and reserved friend, Mr. Darcy, who "owns half of Derbyshire." Bingley is enchanted with the gentle and beautiful Jane, while Elizabeth takes an instant dislike to Darcy after he coldly rebuffs her attempts at conversation and she overhears him insult her. When Jane becomes sick on a visit to Netherfield, Elizabeth goes to stay with her, verbally sparring with Caroline and Darcy.
Later the Bennets are visited by Mr. Collins, a pompous clergyman who talks of little but his patroness, Lady Catherine de Bourgh. After learning from Mrs. Bennet that Jane is expected to become engaged soon, Collins decides to pursue Elizabeth. Meanwhile, the handsome and charming Lieutenant Wickham of the newly-arrived militia captures the girls' attention; he wins Elizabeth's sympathy by telling her that Darcy had cheated him of his inheritance. At a ball at Netherfield, Elizabeth, startled by Darcy's abrupt appearance and request, accepts a dance with him, but vows to her best friend Charlotte Lucas that she has "sworn to loathe him for all eternity." During the dance, she attacks him with witty sarcasm and Darcy responds in kind. At the same ball, Charlotte expresses concern to Elizabeth that Jane's behaviour to Mr. Bingley is too reserved and that Bingley may not realise she loves him. The next day, at Longbourn, Collins proposes to Elizabeth, but she declines. When Bingley unexpectedly returns to London, Elizabeth dispatches a heartbroken Jane to the city to stay with their aunt and uncle, the Gardiners, in hopes of re-establishing contact between Jane and Bingley. Later, Elizabeth is appalled to learn that Charlotte will marry Collins to gain financial security and avoid remaining a spinster.
Months later, Elizabeth visits the newly-wed Mr. and Mrs. Collins at Rosings, Lady Catherine's manor estate; they are invited to dine there, and meet Darcy and Colonel Fitzwilliam, who it transpires are Lady Catherine's nephews. Here Darcy shows greater interest in Elizabeth, especially when she replies to Lady Catherine's jabs with spirited wit. The next day, not realizing that Jane is Elizabeth's sister, Colonel Fitzwilliam lets slip to Elizabeth that Darcy had separated Bingley from Jane. Distraught, she flees outside, but Darcy chooses that moment to track her down and propose marriage. He claims that he loves her "most ardently," despite her "lower rank." Elizabeth refuses him, citing his treatment of Jane and Bingley and of Wickham; they argue fiercely, with Darcy explaining that he had been convinced that Jane did not return Bingley's love. Darcy leaves angry and heartbroken. He finds Elizabeth later and presents her with a letter, which alleges Wickham is a gambler who demanded and received cash in lieu of the position intended for him by Darcy's father. It is further claimed that upon being refused more money, Wickham had attempted to elope with Darcy's 15-year-old sister, Georgiana, in order to obtain her Â£30,000 inheritance, but abandoned her upon learning that he would never receive the money.
The Gardiners take Elizabeth on a trip to the Peak District and visit Darcy's estate, Pemberley, believing that he is away travelling. Elizabeth is stunned by its wealth and beauty and hears nothing but good things about Darcy from his housekeeper. There, she accidentally runs into Darcy, who has arrived home early. He invites her and the Gardiners to meet his sister. His manners have softened considerably and Georgiana takes an instant liking to Elizabeth. When Elizabeth learns that her immature and flirtatious youngest sister Lydia has run away with Wickham, she tearfully blurts out the news to Darcy and the Gardiners before returning home. Her family expects social ruin for having a disgraced daughter, but they are soon relieved to hear that Mr. Gardiner had discovered the pair in London and that they had married. Lydia later reveals to Elizabeth that Darcy had found them and had paid for the marriage.
When Bingley and Darcy return to Netherfield, Jane accepts Bingley's proposal. The same evening, Lady Catherine unexpectedly visits Elizabeth and insists that she renounce Darcy, as he is supposedly engaged to her own daughter, Anne. Elizabeth refuses and, unable to sleep, walks on the moor at dawn. There, she meets Darcy, also unable to sleep after hearing of his aunt's behaviour. He admits his continued love and Elizabeth accepts his proposal. Mr. Bennet gives his consent after Elizabeth assures him of her love for Darcy. In the U.S. release of the film, an additional last scene shows the newlyweds outside of Pemberley showing affection for each other.

Question: who is Elizabeth's sister?
Answer: Jane