Margot Austin, wife of Darrel Austin, artist, and better known perhaps on the West Coast than the East, is doing nice books for children. This is her third or fourth, and once again she has an original touch in both text and pictures and a keen sense of humor. This -- in pictures and text -- tells the story of the kitten and the mouse who palled up to persuade the clergyman to supply the church mouse with proper food so that he would'nt eat the church property.