How much you want to be this was edited before being published? No way her grammar improved this much in one year
I don't know. Adults can learn quickly. I don't even remember any of my classes in any subject that lasted more than a year. One can learn a lot in a year.
Here's a little secret. Most blacks can speak perfect English, whenever they choose. Some speak more than one language.
Rachel may have been 'ignorant', but she wasn't 'incapable'.
Many people learn entire new languages in less than a year. I see no reason Rachel could not improve her grammar/spelling/speech in one year with paid personal tutors.
Besides, I'm pretty sure Rachel was doing the "play dumb in front of the adults" thing during her testimony.