Although the plot itself wasn't something I'd normally like, I was immediately drawn in with the dialogue's realism. It was almost as if the writer had been there before, like she was writing from personal experience, and that's always a good sign.
The punctuation and grammar is of high quality, and what's more the story's opening moments in the library juxtaposed with the incoherent text-speak of the infuriating teenager further strengthen this. I sense perhaps the author has a vendetta against this style of communication. ;)