J.R.
Hi N.,
Often times, when dealing with special needs children, the "normal" discipline is not affective because these children don't understand pain and/or the inconvenience of time out the way we do. What seems to work best (I work with special needs children in the public school system) is social stories and pictures.
Social stories are short stories that should be told over and over to the child explaining how to act in certain situations. For instance, your sister could tell her daughter a social story about table manners: "When we sit at the table to eat, we keep our plate on the table. We only pick up our cup when we are taking a drink and then we set it gently back onto the table. We NEVER pour our drink onto the floor because, if we do, we will then have to clean it up and that's not very fun."....she could also discuss other consequences for negative actions. Note: it is very important that the consequences discussed are carried out after the negative action....it doesn't hurt the little one to get a towel and clean the mess she's made on the floor and it makes a more lasting impression than just griping at her (or even spanking her) will.
Social stories work best when they are told outside of the time to behave. For example, at some point during the day (when it's not time to eat) your sister could sit her daughter at the table as if they are playing a game. Then she could tell her how she expects her to behave at the table, maybe even using play dishes and showing her. Then, when it is time to eat, your sister will need to simply remind her of appropriate behavior..."Susie, don't forget, when we are at the table we keep our plate on the table and we only pick up our cup when we want a drink and then we set it back down nicely. Can you show me how we act nicely at the table today?" Your sister could also get pictures of a child eating appropriately (for instance, sitting, using utensils, drinking, etc.) and lay them out around the place setting for her daughter to follow at dinner time.
Disciplining children with disabilities is a little more time consuming but well worth it in the end. Sometimes parents tend to excuse negative behavior because of the disability. It is VERY important not to let the negative behavior slide because then the child will think the behavior is acceptable. She is relying on her parents to show her how to behave in this world and they will be doing her a favor if they are "a little hard on her" now. She needs to know the appropriate behaviors and she needs to know they are expected of her, no exceptions.
A good website to go to to understand social stories is http://www.polyxo.com/socialstories/introduction.html
Of course, if I can help in any way, please feel free to email me.
Take care,
J.