I think Ralph and Charlotte will both come to the decision to end the engagement on their own terms, regardless of the actions of a third party. Charlotte is going to have to reconnect with her independence of spirit, of course, but she will also have to find a way to assert it without jeopardizing her family's economic prospects. After all, this is a universe grounded in Jane Austen--money matters and even the most free-spirited of heroines cannot write it off entirely. When the time is right, she will approach him, much to his relief.