Is a durable power of attorney legal when signed in a hospital by someone who was admitted with an altered state of mind?

My wife (prior to our marriage) had a MRSA infection with other complications...cellulitis, double pneumonia, uti, shingles...she was admitted to the hospital several times to treat these complications. During her third hospital admission a friend went to her hospital room with a notary public and had her sign a durable power of attorney. My wife had been admitted to the hospital with altered state of mind, experiencing extreme confusion, and unable to follow or understand simple instructions due to her medical condition. The friend who was then her attorney in fact proceeded to place her in a nursing home and sell nearly all of her possessions. She then had her adjudicated incompetent. My wife has since been adjudicated competent and had all her rights restored. Was the durable power of attorney obtained in a legal manner since my wife was in an altered state of mind and unable to understand the possible damage it could result in when she signed it? Is it possible to reverse the actions of her former attorney in fact now that she has been adjudicated competent? Is there a statute of limitations that will effect legal action against the former attorney in fact?