Who and what contributes to the changes in Melinda during Marking Period 3?

I think that Mr. Freeman makes the main difference. Mr. Freeman can tell that Melinda is stuck in her problems: he knows she needs a way out. He uses art to get Melinda to express her anxieties. He gives her a book with various Picasso paintings. Although not interested in Picasso's early works, she is captivated by Cubism. She draws a Cubist tree, which gives her the validation to move on.