A Pair of Dancing Brown Eyes

A Pride & Prejudice variation. What if Elizabeth and Jane were the daughters of Mr Bennet's first wife, Eleanor, who died in childbirth bringing Elizabeth and her twin brother (who also died) into the world? Distraught, a few years later, he marries Fanny Philips who turns out to be a vicious and vindictive woman who holds Elizabeth to blame for all the wrongs in her life. The girls are forced to leave their family home to live in Lambton with an aunt and uncle, and they meet the Darcy family. What means will Fanny enact to revenge herself for all the wrongs she feels Elizabeth has done her?