How does the third sentence ("However, Blume also has. ...") support the main idea of the paragraph?

It tells you that the author once wrote for children but has changed her focus and preference to adults.
It tells you that the author has great talent because she writes good stories for children as well as adults.
It points out that the author has written more books for children than she has written, or plans to write, for adults.
It points out that the author only writes stories that she expects will win awards or sell well among adults.