Well, I think you have a lot of love for your characters and I think you have a vivid imagination, but the way this piece was written didn't do a thing for me. It was very cold and distant; I felt like I didn't really know these people at all, and I kept wondering why they treated each other so badly. Maybe you were trying to create a cold and distant kind of ambiance so we could feel their isolation, but honestly, I just kept scrolling down to see how much I had left to read. I don't mind a depressing story, but this was TOO depressing.
I did like the, "writing words that nobody reads" line, but did it have to be used so much? As the story went on, it lost some of its impact. Just something to think about.
I wouldn't scrap the idea completely, because I think you could write a good story based on these characters, but I would really get in their heads and ask them a few questions. Why did the parents stay married for so long knowing they didn't really love each other? Why would a father stop loving his daughter because his son died? Why would a little girl react to the news that her father was dead with a simple, "I know" instead of bawling her eyes out? Why didn't her teachers want to read her essays? These things could be explored so the story could flesh out and become a living, breathing thing instead of just words on paper. Good luck with the fine tuning.
"An intellectual says a simple thing in a hard way. An artist says a hard thing in a simple way." -Charles Bukowski
"And by the way, dearie, your punctuation sucks canal water!" -The ghost of Vivian Vance