Mary Poppins by P. L. Travers

From chapters.ca:
Who can slide "up" banisters, banish naughtiness with a swift "Spit-spot," and turn a make-believe sidewalk drawing into a lovely day in the park? Mary Poppins, of course! This omnibus edition combines the two Mary Poppins classics, "Mary Poppins" and "Mary Poppins Comes Back," that inspired both the 1964 movie and the Broadway musical.

Sequels: Mary Poppins Comes Back, Mary Poppins Opens the Door, Mary Poppins in the Park, Mary Poppins From A to Z, Mary Poppins in the Kitchen, Mary Poppins in Cherry Tree Lane, and Mary Poppins and the House Next Door.

Surprisingly, I didn't like the books much, but I do believe in reading the books that movies are based on.