Is it legal for a power of attorney to put her name on everything and ignore the will after death??

So my aunt became power of attorney over my grandfather after my grandmothers death because of his dementia. She not long after put her name on the cars, house, and bank accounts. My grandparents did have two wills we found in their safety deposit boxes. My grandfather died over 2 years ago. The will has not been read or dealt with and my aunt has taken control over the house, cars, bank accounts, and all the property in the house. Is that a legal thing she can do?