Originally Posted by MotorcycleChick
Was it wry neck?
Yes, it looks like that's what it was... I'm learning something new with every unfortunate loss :( Reading up on it, I see that it can be a hereditary defect, but then it also says it can be caused by vitamin deficiency or injury. Any of those could have been the cause, since she was the smallest she didn't compete well with the other chickens for food and I did give them leftover corn from the garden the other day (they do have full access to regular grower feed pretty much all the time though). She wasn't feather pecked or anything, but I can see that another chicken could have given her a peck to the head that would have gone unnoticed too.
Regarding the possible hereditary cause, should I contact the place I got her (a little homestead farm) to let them know? None of the other chickens seem to be negatively affected by the corn we gave them, even the one RIR who is a bit smaller than the other birds.