Such a wonderful thing you are doing! I have a 9 yr old autistic grandson and yes these blankets are a life savor. They help so much when the child is feeling overwhelmed and can't deal with his emotions. An autistic child has so much to deal with that is hard to imagine if you haven't been around someone who is autistic. They need the physical stimulation of sensory(textures)to be calm. Zach has what we call meltdowns and this is one way of calming him.
My daughter made her own version of one. They are quite expensive if you buy one.