In the novel, To Kill a Mockingbird, what do the characters in the story think about Miss Maudie?

Jem, Dill, and particularly Scout generally adore Miss Maudie. She is like an aunt but they (Scout and Jem) clearly enjoy her company more than they do with Aunt Alexandra. Miss Maudie allows them to play anywhere in her yard as long as they don't kill the flowers. She makes cakes for them and when Jem and Dill are off doing "boys only" things, Scout goes to Miss Maudie: 

In summertime, twilights are long and...

Jem, Dill, and particularly Scout generally adore Miss Maudie. She is like an aunt but they (Scout and Jem) clearly enjoy her company more than they do with Aunt Alexandra. Miss Maudie allows them to play anywhere in her yard as long as they don't kill the flowers. She makes cakes for them and when Jem and Dill are off doing "boys only" things, Scout goes to Miss Maudie: 

In summertime, twilights are long and peaceful. Often as not, Miss Maudie and I would sit silently on her porch, watching the sky go from yellow to pink as the sun went down, watching flights of martins sweep low over the neighborhood and disappear behind the schoolhouse rooftops. (Chapter 5) 

Scout discusses Miss Maudie at length in Chapter 5 and suggests that she is as much of a pal as an adult role model. This sums up how they feel about her: 

She had never told on us, had never played cat-and-mouse with us, she was not at all interested in our private lives. She was our friend. 

In Chapter 24, Aunt Alexandra gives Miss Maudie a silent "thank you" or nod of approval when she criticizes Mrs. Merriweather's racist hypocrisy. 

Atticus also admires and respects Miss Maudie for being open-minded and a decent role model for the children. She is also friends with Stephanie Crawford because that is who she stays with after her house burns down. In general, Miss Maudie is respected and liked or loved by the aforementioned people who are significant parts of her life.