If your mother wants you to be able to use her checking account to pay bills after she is gone, then she needs to arrange that with the bank during her lifetime. She would designate you as either the beneficiary of the account or an additional signer. The bank will have forms for this. You will not automatically become Executor, Administrator, or Personal Representative of the estate (I assume this is what you mean by "head of the estate"). A probate court would have to appoint you to one of those positions after your mother passes. But if your mother makes the arrangements with the bank, you will not need a court appointment to use her checking account.
Answered on Jun 19th, 2013 at 3:05 PM