I agree with jamesmichael. You need to pick a single protagonist to drive the story.
Also, from what I can see in the way you have written your log line, the girls' discovery of their demigoddess/guardian status would be the inciting incident of the story but "discovering" would be an action on part of the girls.
I think you will need to take out "discovery" (action) and change it to something that happens (event) to the girls as an inciting incident.
ie: When a geeky pushover and her friends are bestowed the powers of XYZ, the geeky pushover and her friends will need to fight an evil goddess or the world will be enslaved.
Not the best logline but just want to demonstrate that the inciting incident is something that should happen to a character not something a character does.