Which of the following individuals is an eligible educator and may deduct up to $$300$ of qualified educator expenses? $($None of them received any reimbursements.$)$

Mr$.$ Francis is a teacher's aide at the local high school. He taught part$-$time. He worked $600$ hours during the year and spent $$400$ on teaching supplies used in his classroom.

Mr$.$ Chang is a fourth$-$grade teacher. He taught full$-$time in a classroom and worked more than $900$ hours during the school year. He spent $$750$ on teaching supplies used in his classroom.

Mrs$.$ Sullivan is a professor at the local community college. She taught full$-$time during the entire school year. She spent $$500$ on teaching supplies used in her classroom.

Ms$.$ Rowling homeschools her three children. She spent $$950$ on books, computer software, and classroom supplies.