How can I find help for elderly sister and her caregiver?

Her son is doing his best. He is living with her, but he is disabled and can't help her with personal care. It breaks my heart to hear how bad it's gotten. I don't know why he isn't getting help. Whether there's none available, or if he is afraid of what will happen if an agency comes in. I am in another state, also disabled, but could possibly go there to help him get help. I don't know where to start. There are other relatives there, but he may not be confiding in them or reaching out to them. I think she probably needs long term care, but the nursing homes are awful. They live in New York State. If anyone can direct me to any resources or services I would be grateful.