Belle studies. She really doesn't get as lonely as Beast - and maybe he and Chelise can fall in love if she stays out of their way, and then the curse will break and Belle can ransack the library and go home, that would be fine. She works.
Then he murmurs in her ear, "Your papa is crying."
And presently, "Let's go home and start looking through books, shall we?"
Eventually she has her supply of magic books extracted. Including those that are in foreign languages. "You can read again without hurting your eyes, I assume," she observes.
Belle hands him one of the foreign language books that they never got around to categorizing, and then consults her index for which of the categorized books is most likely to contain castle-building instructions.
Eventually Belle finds something. "Here we are," she says. "I think if I do this right, I can even get it to organize the library in the process. I do need to design the layout, though, and decide what it should look like."
"Is that your only preference on the subject?" laughs Belle.
"I don't know, I've never been married before," he laughs. "Is there a reason not to?"
"No, not really," she says. "Does the size of the old castle sound about right to you?" She's gotten out a notebook and begun to sketch a floorplan.
Sketch sketch sketch. "The spell will be able to fill in a lot of little details by itself, and it'll be alive the way the old one was so it'll be easy to change. We could put it some fifteen minutes' walk into the woods and live there tonight."
"Yes, the alternative is having the wedding night with just a wall between us and Charlie," she murmurs with a nervous smile.
"You're going to have to show me how it goes," she murmurs. "I have read more books than my father knows about, but not as many as it would take to actually set him on fire with distress."
"Well," he says, "I am glad your father is not on fire, and I will be happy to show you everything I know."