Social class plays a large part in Jane Austen's novels. This is reflective of the time period, as rank meant everything during the Regency and Victorian eras (although Austen's novels are set in the early Regency).
The novels feature plenty characters of rank, and characters who transcend rank, like Elizabeth Bennet.
The highest ranking Jane Austen heroine at the beginning of each respective book is arguably Anne Elliot, as she was born the daughter of a baronet, however her rank lowers slightly when she marries Frederick Wentworth. The person of the highest rank in all of Jane Austen's books is actually Lady Dalrymple, as the widowed wife of a British peer, the late Viscount Dalrymple. Although Catherine de Bourgh is the daughter of an earl, the wives of peers took social precedence over the daughters of peers, which means Lady Dalrymple ranks higher than Lady Catherine, even though she is only a viscountess.