Complex sentence: Bingley does consent to give a ball, so Amanda hopes that events have returned to coincide with the book, but at the ball Darcy convinces Bingley not to marry Jane, because her family, influenced by Amanda, only want his money.
Split into simpler sentences: Bingley does consent to give a ball, so Amanda hopes events have returned to coincide with the book. But at the dance, Darcy convinces Bingley not to marry Jane, because her family, led by Amanda, only want his money.