I luv these kinda stories when a different era is the setting.
The guy has an interest in her earnest nature and will to live as she is (not being a escort or forced bride) even if she's still very naive because of her age. But he himself has as much to learn as she does.
As realistic as child brides and grooms were in that era, in this situation, thought still forced, still gives both sides the free option to back out when the time comes rather than an end all be all scenario.
I can't wait for more XD