There are many different families, all with different dynamics. Consider Darcy and his sister. He has an extremely fond devotion towards her, is good friends with her (as it is alluded to the fact that he told her about Elizabeth), and she reciprocates those feelings. Then there is the infamous Mr. Wickham, who, though growing up like a brother to Darcy, earned Darcy's disrespect forever through bad actions. Darcy's father seemed a kind man that was fond of all of his children, and Wickham seems to have manipulated that relationship a bit, or at least taken it for granted.
The Bennett family is more dynamic; Liz and Jane are very close together, but Liz doesn't share that same bond with her other sisters. In fact, she is aware of her other sisters' lack of social tact, and finds them embarrassing. She holds an interesting relationship with her high-strung mother. She tolerates and helps her, without endorsing her sometimes erratic behaviors and beliefs. She seems to be close to her dad; he is fond of her and she of him. She turns to him for help when Collins proposes, and he supports her.
The other families in the book play such minor roles; extended family offers a good vacation for the girls here and there, and are good for favors or mentions every once in a while. All in all, the relationships are diverse, from disdain to fond affection.