critically analyse the family of bennits?

That's a pretty big question so I'm going to hook you up with the GradeSaver character list. Really it is much the same as I would tell you,

http://www.gradesaver.com/pride-and-prejudice/study-guide/character-list/

I think the important thing to remember about the family as a whole is that they want to improve their station (class) in life. The parents have only daughters which was not the best economically. Marrying well would have been their only shot at improving their fortunes.