Think my neighbour has groomed his daughter

Into becoming disabled. Now I've seen his daughter, she not stupid nor lazy when I first met her. Over the years I have seen her father treat her as though she retarded, picked on her, even bullied her to the point she doesn't want to anything to do with him anymore and because of that she is now kept indoors, unable to go outside to interact with any of the kids. Over time I've noticed she gotten fat, slow, unkempt and barely able to say a word. Now the reason I believe she been groomed is due to their other disabled son was on his last rope of life for two years and claiming disability for him. Because for the past two years all the conversation I had with the father was nothing but his child benefits not saying how he is doing, even tried to put him on insurance and that when I thought about it. Does he only care about the money he gets from his children and when his Son passed away and I was at his Funeral. He did not look sad at all and lately he been getting angry because he not getting any disability money for his daughter