It must be extremely upsetting, Nothing about this is easy.
But every time you come up against an obstacle just remind yourself, Your mothers wishes 2 years ago was very clear - she stated in writing that she agrees you are the person to look after her affairs. It was her stated wish that you step in for her when she became unable to do this for herself.
While you may swing over and back and consider your sister is right or wrong at various times all you can do legally is follow the documents signed. Just keep that to the forefront of your mind.
But every time you come up against an obstacle just remind yourself, Your mothers wishes 2 years ago was very clear - she stated in writing that she agrees you are the person to look after her affairs. It was her stated wish that you step in for her when she became unable to do this for herself.
While you may swing over and back and consider your sister is right or wrong at various times all you can do legally is follow the documents signed. Just keep that to the forefront of your mind.