I read through your posted chapters, and although "Cookie" is very well written, it just isn't for me. It starts off dark, and only seems to be getting darker. I'm generally not a huge fan of stories where life shits on the protagonist constantly, especially since there seems to be no hope for her situation to improve.
I think my biggest issue with the story though, is that it just doesn't really feel believable to me. The abuse from Cookie's father and the rest of her family is plausible, but the fact that the teachers are complicit, even going as far as to put her in the boys' gym and sex-ed classes seems ridiculous to me. Maybe that's a time period thing, and it would have been possible in the 50s and 60s, but I doubt it.
The last chapter was the worst, in my opinion, because you offered hope that things might start to get better, only to kill off the character who might be able to help Cookie. (I know that Mrs. Vi is a real person, so you didn't really kill her off, but it amounts to the same thing.)
I do think the story is compelling, which is probably why it affected me so negatively. I have rated it a 10 because although I didn't enjoy the subject matter, I did read through the whole thing hoping that things would improve for Cookie, and felt engaged the whole time without any technical errors standing out to me.
I may read Chapter 25 when you post it, but if things don't improve for Cookie, it'll probably be the last chapter I read.