Gran was treated like an indentured servant, not family. She worked like a dog. She treated your mother the way she had been treated, but probably was unaware of the fact she was even doing it. I think a lot of the reason I don't like to talk about home, or why I avoid coming home is I am still a hurt child inside. There are things you just don't get over, however hard you try.
All children know more, remember more, etc.
I see it in my neighborhood here in Boston, and I know it was true for myself and you. I would come home with all A's and incredible reports and never get even a pat on the head. My mother never read to me, and no one would sit and listen to me read when I brought my books home from school. She nagged me about boys and to get after one from the time I was 14. She nagged me so I wore heavy make-up, which made my skin even worse than it already was.