It's Dr. Lily to the rescue! After witnessing a car accident and helping a little boy who was hurt, Lily embarks on a mission to become a 'great healer' or healthcare professional, and no one's going to stop her. Lily starts watching medical shows on TV and checking out health books at the library, but that's not all -- she signs up for a body class for girls where she learns about all sorts of things including getting her period and her changing body. As usual, Lily goes overboard, and it's not long before she's trying to change the Girlz Only Club into a health class---fitness plans, label reading, exercise, and more. However, her friends aren't too thrilled about her newfound passion, and when they stop wanting to be around her, Lily has to choose. In the end, Lily learns and important lesson about friendship that she'll never forget.