Thank you for your question. I cannot write your paragraph for you, but I can give you some good ideas. Scout is indeed a very intelligent little girl. How do we know? What does she say and do that gives us this impression of her?
One of the first things we learn about Scout is that she is already a good reader before she even starts school. Scout explains how she learned to read in Chapter 2. She can't remember when she could not read hymns in church. She says that "reading was something that just came to me." She also talks about learning to read while sitting in Atticus' lap in the evening, learning to read whatever he was reading.
Another sign of Scout's intelligence is how she can figure things out on her own. For instance, at the end of the novel, she figures out that the man who saved her and Jem was Boo. Nobody told her. Scout does a lot of thinking in the book, certainly a sign of intelligence. Check the eNotes links below for more good ideas about Scout.