Mother and daughter have a joint account. Mother has passed away but prior to death she told daughter that what was left in account was for her

Mother tells daughter that the joint account she has established with her daughter is her daughters after the mothers death. Is this legal. Mother has passed

Mother did not have to tell daughter anything, since it is a joint account, the daughter has full access to the money.

Thank-you Fr Chuck, Question- Even in Louisiana?

Is the account in a state bank or a federal bank.