In the book To Kill A Mockingbird by Harper Lee, when is Scout being ignorant? (quotes and page numbers)
In Chapter 3, Scout scolds Walter Cunningham Jr. for putting a lot of syrup on his food. Atticus silently reprimands her by shaking his head no, but Scout yells at Walter again. Then Calpurnia brings Scout into the kitchen. Calpurnia tells her to respect anyone who is company, even if they have different eating habits. Scout replies, "He ain’t company, Cal, he’s just a Cunningham-" This is an elitist attitude. Saying this, Scout implies that she (and those of her family and/or class) are better than people like the Cunninghams. This is obviously contrary to what Atticus and Cal have taught Scout.
Near the end of Chapter 12, Scout reveals that she had been ignorant about Calpurnia's "double" life. In this chapter, Cal takes Scout and Jem to her church. The children see a part of Cal's other life, including a different culture and way of speaking. Scout notes:
That Calpurnia led a modest double life never dawned on me. The idea that she had a separate existence outside our household was a novel one, to say nothing of her having command of two languages.
At the end of the chapter, Scout asks if she can come visit Cal sometime and this suggests that Scout wants to learn more about this other part of Cal's life.
One of the major themes of the book is considering the perspective of others. Scout, Jem, and Dill all mock Boo Radley without considering his feelings or his actual story. It isn't until the end of the book that she truly considers Boo's perspective and what this means. In the final chapter, near the end of the book, Scout considers:
Atticus was right. One time he said you never really know a man until you stand in his shoes and walk around in them. Just standing on the Radley porch was enough.
This shows that Scout was ignorant, but now has a new perspective on things.