conservator
noun [ C ]
LAW US uk/kənˈsɜːvətər/ usa person who is chosen by a law court to look after the property of a person who is not able to do this for him- or herself, for example, because of illness:
The conservator is given the authority to make financial decisions and handle your financial affairs, when you lack the capacity to manage them on your own.
appoint a conservator
conservatorship
noun [ C or U ]
I need to set up a conservatorship to use my mother's assets to pay for her nursing care.