It's Dr. Lily to the rescue!
After witnessing a car accident and helping a little boy who was hurt, Lily is 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 health class for girls at a local health club.
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, etc. However, her friends aren't too thrilled about her newfound passion, and when her friends stop wanting to be around her, Lily has to choose.
In the end, Lily learns an important lesson about friendship that she'll never forget.