These are options but I would add Charlotte judged all options but marriage dishonorable. She limits her options herself—I feel that is her right. She obviously feels marriage to Mr. Collins is preferable to all other options. Are you equating Charlotte’s choice of Mr. Collins to prostitution? I do not think Nan Duval was suggesting that—she can correct me if I am wrong. IMO that would be an incredibly harsh judgment as she believes she can be happy with him and must have considered that marrying him includes an intimate relationship.