This is an accepted solution.
The text says it all pretty much. Seems like you need to make a linklist called "girly collection". So go to Online Store > Navigation. Then create a new navigation called Girly Collection ( it's handle will be lowercase so don't worry about that ). It's a little confusing because it says you don't have a Girly Girl link list and also says you don't have a link list set to girly-collection. I assume it's looking for the collection handle, so if you make a navigation called Girly Collection I think the code will probably figure it out.