Miss Maudie has an especially strong impact on Scout's life, teaching her the ways of the world from the point of view of a woman not as deeply entrenched in traditional southern notions of womanhood as other women, such as Scout's aunt. Also, Maudie has known Atticus for a long time, and therefore can explain certain things about him (such as his ability to shoot) that no one else would. Maudie is outspoken, has values similar to those of Atticus, and can bake fine cakes to boot, all three attributes comprising a type of nourishment that the children need. Here's an example: Not long after the trial, Scout is participating in a missionary ladies' party that her aunt gives, and Miss Maudie is there. Scout is called upon to act "like a lady" in ways she abhors, and even worse, tease her about goiong to court and sitting with Negroes during the trial. She wants to lash out, but then Maudie reaches over and quietly holds her hand, consoling her and silently advising her to say nothing. "Miss Maudie's hand closed tightly on mine, and I said nothing," Scout reveals. She is one more example of womanhood which contributes to several other (her aunt, her teacher, Cal, Miss Stephanie, etc) against which she defines herself as she grows up. More than the other female characters, Maudie fills in the vacuum of "mother" in Scout's life.
Miss Maudie becomes Scout's friend during one summer when Scout feels Jem and Dill are playing games that she doesn't want to participate it, mainly about Boo Radley. Her main impact on the children is the fact that she can tell them things about Atticus that he would never tell them himself. When the kids have a question, they can go to Miss Maudie and get a straight answer. She admires Atticus and understands why he does certain things. She tells them what a good shot with a rifle Atticus is, something that Jem and Scout would never have thought about their father. She explains the reaction of the people in the town to Atticus' defense of Tom Robinson. Miss Maudie is a sincere, caring woman who always tells Scout and Jem the truth and never treats them like children by talking down to them. She's able to tell them things that Calpurnia, as a black woman, couldn't discuss with them. She helps them to understand Atticus a great deal more, and she has a positive impact on their lives.