100% chance it was sent by a ween, could have been Kengle but lots of people who talked to chris were no doubt aware of Nick. I don't see Chris picking it up because it doesn't have a pony or other cartoon animal on the cover, and it isn't about him.
I think Barb might also be an autist, autism in women comes off very different then men. I mean, she sleeps all day, any time I've heard her speak it sounds like a retard speaking (the hick accent doesn't help), believing to be related to royalty, the hoarding, the fear of chris leaving, feeding dogs chicken soup, etc. Look at the graduation photo she just dead stares at the camera with a burger in her hand, even a candid shot most people would feign a smile or a goofy face. She just dead stares at the camera like a retard.
That or they were truly just stubborn dumb hicks too proud to have a retard son. It's not like sending him to a special school would be like committing him to be lobotomized and undergo shock therapy. I don't understand their rabid determination to mainstream him, to the point of trying to take legal action.