Nichelle, 
 
My mentally retarded sister is now 60 years old and she definitely had PWS, but at the time when she was a child, there was no such diagnosis. My Mother tried to provide structure for my sister which was always corrupted by my Father. She grew up throwing tantrums in order to manipulate my father into giving in, which he always did. She ate herself to severe obesity and numerous medical problems. I endured several beatings from my father as she told him I hit her. While I was being "disciplined" she would stand by and laugh. I grew up with a lot of anger toward my parents over what I suffered with her being in the house. She did no wrong. 
 
When she started to throw her hips out of joint and being self destructive with hitting and biting herself to the point of bleeding, she was evaluated by several specialists. First of all they put her on a tranquilizer. They strongly recommended she be placed in a school for the mentally retarded where she would have the structure she desperately needed. She would by this time, literally knock my mother and me to the floor when ever she felt like it and then be as sweet as could be to good ole Dad. He would get physically ill if he tried to discipline her. After much fighting with the specialists and our local physician's support she was send to a boarding school. Occasionally she would come home for a weekend and the change in her behavior was dramatic. Then the fight to take her back to school as Dad just couldn't stand it without her home. Finally he went to school and brought her home for good. We tried locking food up in the cupboards and keeping her out of the kitchen but it was impossible. 
 
Several years later, when she was out of control and in her 30's she was put in the state school for the mentally retarded. She loved it there. No body stared at her she would say. She behaved and lost weight. Then the state facility closed and they dropped her off at my parents home one day. 
She was out of control in no time and actually battered my mother so bad she sustained a fractured arm. When the physicians found out what happened, they told my father in no uncertain terms that she would be placed in a group home voluntarily or they would go to court and have her removed from their home. She was placed in three different group homes before she felt at home and has been there ever since. She always wants to go home after a few hours with my parents. It's hard for them to have her refer to the group home as her home, but it is. 
 
Group homes or placement outside the family home is not for everyone. With your situation of having other children in the home and being a single parent, this could be an avenue for you to consider. You seem to have a lot of stress and anger with your current situation. Please do not take it out on this special needs child. Do what you feel and know is best for this child. If she needs more structure they you are able to provide at this time, please consider a group home. You can still be an active part of her life and need feel no guilt. You may be doing her, yourself and your other children a great service. But please, no more name calling, no hitting her. It just doesn't work. 
 
I'm praying for you. 
Dee