] Do you think the relationships have the sisters relying upon their brothers so far? Is there any support or instruction offered by the girls?

Someone pointed out earlier that IT and JT were like tag-teamers when it came to get each other married. JT no doubt introduced James to IT with the hope of her being able to draw him in (if I may borrow a phrase from Lady Catherine). IT becomes friends with Catherine to promote both her own marriage and her brother's.

Elinor and Henry are very found of each other, but I don't think we've seen them to much to see if they rely on each other for anything. Except that Henry can promote his relationship with Catherine more easily with his sister's help.