@croydon - She is an interesting case, but do remember that she was only struck with her disabilities when she was a toddler and became sick with something that was probably scarlet fever.
She had almost two years of being able to use her eyes and ears and to drink in the world and shape her brain.
If she had been blind and deaf from birth and they had only attempted to talk with her at eight years of age, she might not have been so capable of understanding.
There have been cases where children have been raised by wolves or other animals or in complete isolation and they are almost always unable to adjust to human life if they aren't recovered by the time they are six or older. Young children simply need to learn to talk and be exposed to human communication or their brains won't develop the ability to do so after a certain point.