My Mom I feel is being bullied by my brother and his wife. She has been given the title of Government payee over my Dad's Social security. However they were unable to prove that she was unable to think for herself as she was proven to be well within her right mind and still very capable of thinking for herself. They are pressuring her by taking things from her. She has asked me to be her guardian, what is my next step? I live half way across the country, what do I do? This is very important to us both.
Does your mother have a will? I would think that with a will that you with a POA could take legal steps against your brother who is taking things from your mother.
You might look into POA while she's living and having her make you executor of her estate after death. Then you should be able to thwart attempts to steal from her by the bad brother and wife.