What is the main conflict in Stargirl by Jerry Spinelli?

When Stargirl walks into the Mica High School she sparkles like an odd gem as she sings Happy Birthday with her ukulele in the lunch room or performs random acts of kindness for strangers. Enchanting Leo Borlock and then the school she inspires a new attitude in her classmates; until the school begins to turn against her because she is still the odd girl out with her unusual habits and kindnesses to rival football teams.