Sophie and Sammy's Library Sleepover (1993)
Sophie loves to read books and Sammy loves to rip them and sit on them and build castles out of them. When Sophie goes on a library sleepover, she decides to make one for her brother. In real life, I couldn't attend the sleepover---I had no one to watch my son, who ran amuck in libraries. So I made it up.

“Book lovers, especially librarians, are sure to find much to enjoy in this cheerful story about how Sophie helps her little brother learn to treat books. Caseley does an admirable job capturing the energetic fun of the library…a book with a purpose, but irresistible, nevertheless.” --Horn Book