The problem with having an understanding is that it's indefinite, and on what grounds is it broken? Anne could have been waiting years for CW to distinguish himself. What if 5 years down the track, he still hadn't earnt enough money to support a family. Would she then in good conscience be able to break the understanding without feeling she was betraying him? Would waiting that length of time to start looking for someone else mean she'd already lost her youthful bloom which would attract a marriage partner? Or would she continue to wait until he distinguished himself beyond the point of hope?