A fun way to execute this YW activity - have one candy bar for each YW - but each candy bar being different. If you have more YW than candy bars listed, you can make up some of your own scenario's or have multiple girls have the same bar. Take turns reading about each candy bar girl, then discuss how each one can be/do better. Apply these to their lives. Have them think about all the good they're doing and if they need to be doing more things pertaining to the basic gospel principles.
Recommended Additional Resources:
Dallin H. Oaks video on GOOD BETTER BEST
Dallin H. Oaks article on GOOD BETTER BEST