Bank Account for Payee and surviving child

I am the payee for my daughter's survivor benefits from her father. We have an account set up for direct deposit naming me as payee and my daughter has beneficiary. My daughter is an adult; however, the bank refuses to allow her access to the funds. I monitor everything in the account, yet I have allowed my daughter access so that if she needs money and I am not available, she will not be stranded. This particular account was set up in 2001 or 02 when my military husband and I were transfered to that particular location. Is there something in the Medicare guidelines that prevent the named beneficiary from withdrawing funds from this type of account?