Who is Bella Wilfer from Our Mutual Friend and what is their importance?

Bella Wilfer is a young woman from a poor family who dreams of being rich. She is the daughter of Mr. and Mrs. Wilfer and the sister of Lavinia Wilfer. She is promised as a bride to John Harmon, but loses her chance to marry rich when he is reportedly found dead. Bella was not looking forward to marry him but was looking forward to being a rich man's wife. She moves in with the Boffins, and continues to hope for a rich husband until she realizes she has fallen in love with John Rokesmith, really John Harmon in disguise.