The Duke of Derby

Elizabeth Bennet receives a letter stating that her father is suddenly the newest Duke of Derby while she is visiting Charlotte Collins in Hunsford. The revelation throws her mind into turmoil since the letter contains both too much and not enough information. She knows her life is about to change dramatically, but she is unsure what that new life will look and feel like.
The day after this momentous revelation, Mr. Darcy makes his infamous proposal, declaring his love for her despite her poor relations. With Elizabeth’s new knowledge, she responds significantly differently to his offer, though she still declines him.
Not long afterward, the new Duke of Derby takes Elizabeth and Jane to Derbyshire to learn more about their new home and their new situation. While there, she once again encounters Mr. Darcy, though this time it is on more friendly footing.
The newest Duke of Derby does his best to help his family adjust to their new life, and he keeps his daughters safe and happy as they each discover both the exciting and challenging aspects of their new lives.

Of course, Elizabeth eventually marries Mr. Darcy, but each of the Bennet girls finds her own happiness in her own unique way as this story unfolds.