Why is Miss Pross jealous of Darney and Carton?

Miss Pross has devoted her entire life to Lucie. Both of these men play a large part in Lucie's new life..... one, a friend, who wished for more..... the other, the man Lucie falls in love with and marries. Miss Pross has been like a mother to Lucie, and she couldn't have love her more had she been her own daughter.