First thing's first, you are a bonafide screenwriter. I can tell that by your writing. You have a very unique voice and it works well with the script you have written. There isn't much to tell you about the craft of screen writing because it's obvious that you have put much study into it. You write like someone that has been doing it for years. You know what you want to say, you know what you want your characters to do and you know where you want the story to go. You write with a lot of purpose is what I am trying to say.
But this particular story, I am not so sure of it's viability. The genre you have chosen to write this story in is Thriller. It's a genre full of Spy epics, Terrorist, Bank robberies, Classic Whodunits and so forth. But in the story you have written we are following a 14 year old girl, Jeanie, and her quest to make friends and her coming to the understanding of herself while finding her place in the world around her. The only teenage girl thriller I can think of is Hanna and if you have ever watched that movie you would understand why it is definitely a thriller. She is basically like Jason Bourne, a prodigy for her age. The script doesn't play like a Thriller until the last action sequence with Danny, it's more a coming of age story with a gruesome twist to be honest. I don't know what genre that would be but Thriller fans who would read the script or watch the movie would be a little disappointed by the story not being true to the genre.
Don't get me wrong the story is a really good one but not for the kind of genre you are writing it in. That's basically my only critique of the script. As I said, you are a good screenwriter so everything as it pertains to story is up to standard but just be mindful of the audience you are crafting a story for. Learn the elements of the particular genre you want to write in and ensure your story is respectful of that genre, or else people might be disappointed in what is being shown to them.
