I seem to be stuck on Mary, but there is a difference in how she is portrayed in the novel and in P&P2. In the novel she works hard on her accomplishments. IMO she wants to gain her father and elder sisters regard by pursuing those areas they seem to esteem.

In P&P2 Mary seems more resigned in her attitude. She sighs whenever she sees her sisters pursuits of officers, clothes and gossip. She attends more to how she can impress on the society of Meryton. Or as Vanessa M wrote in another thread she "seeks to outshine her elders".