If the account was opened as "joint tenants with rights of survivorship" (JTWROS) then nothing has to be done or reported, and the account is not part of the estate. It's now the daughter's money, and nothing has to be reported to anyone. The estate will report the income though, and the estate is liable for any taxes due. The surviving joint tenant reports nothing, and pays nothing in the way of taxes to any taxing authority.
The surviving tenant is only liable for the interest on the account, that accumulated and was paid after the other account holder passed. The estate is responsible for taxes on all interest earned and paid before the elderly relative passed.
