I love the scene in Chapter 59 when Elizabeth tells Jane about her (Elizabeth's) engagement to Darcy. Jane is shocked, of course, because she didn't know anything about Elizabeth's change of feelings at Pemberley. But my favorite part is when Jane very seriously tells her sister not to marry without proper feelings for Darcy:
"And do you really love him quite well enough? Oh, Lizzy! do anything rather than marry without affection. Are you quite sure that you feel what you ought to do?"
These two sisters are such a wonderful example of putting the feelings of each other first that it makes me long for a sister (sort of!).