A text-heavy story needs paragraphs; walls of text are hard to read. I'd also outline the text to the left, instead of centering it. Ideally, this would become more of a visual novel, with text broken into small chunks of dialog, written out in a steady pace, so it's all easier on the eyes and attention span.
I like the premise of interacting with the main character through written messages, but with a story like this, I also prefer to know my own role in it; am I a character in Mable's life, am I a random voyeur shouting get-well messages at her? I personally feel like the story would benefit from making the player's connection to the character(s) more clear.