Why did Diane give the solution to her mother at the end of the talented girl movie?
My understanding is that she doesn't want her mother to see her publish this thing. Her mother wants her to succeed, but she has a deep grudge with her mother. She doesn't want her mother to be happy because of this. But at the end of the film, her mother is going to do a series of work to help her publish ... Her mother may also regret her paranoia when disciplining her daughter.