I hate family fights, but it seems when mom and dad die, siblings often get into this type of dispute. If your sister, as agent, holding a fiduciary duty to utilize your mother's Social Security for her benefit, utilized for your sister's benefit, this is not only a breach of her fiduciary duty, assuming mom was not legally incapacitated, it mat arise to elder abuse and a criminal act of theft. The attorney who draft the documents, assuming mom was clearly suffering from Alzheimer's disease, may also have exposure. Consult with your SC attorney. We are unable to provide advice as out of state attorneys and as you are represented by an attorney.