Who is Catherine Sloper from Washington Square and what is their importance?

Catherine Sloper is a twenty year old girl when the novel begins. Catherine is the daughter of Dr. Sloper, a man who was terribly disappointed to be left with a female child instead of the son he had once and lost. However, Dr. Sloper believes he has done his best by his daughter despite his disappointment that she is not as beautiful or as clever as his wife was.
Catherine is not attractive and leans toward the overweight, therefore she does not have a great many beaus. When Mr. Morris Townsend begins courting her, it is the general consensus that he is after her money. Catherine does not care, however, determined to marry him anyway. When he breaks her heart, Catherine refuses to ever take another beau, and instead spends her life alone with her aunt.