How does freaks grandparents make up for having bad thoughts about max?

Freak's grandparents ultimately come to terms with their initial negative thoughts about Max by recognizing his genuine bond with their grandson, Kevin. They see how much Max cares for Kevin and how their friendship enriches both of their lives. This realization allows them to appreciate Max for who he is, rather than judging him based on preconceived notions. Their acceptance fosters a supportive environment for both boys to thrive.