Wikisimpsons - The Simpsons Wiki
Ms. Melon is Bart's new teacher, when he goes to the gifted school. Her teaching methods are very different than Mrs. Krabappel's, she lets the children learn at their own speed and lets them do their own thing. In most cases this works fine because her students are very intelligent but when Bart got to the school and he didn't know what he was doing, especially in chemistry, this method became dangerous. She also appeared a few other times around Springfield.
She was seen at the Springfield Dragway with her husband and son when the power plant reserved it for an employee event.