My mother fought for 5 years to receive her Social Security benefits. Finally her lawyers sent her a letter stating that the fight was over and that she would be receiving a letter stating what her monthly amount would be. That was January... by September my mother was dead and had not received not one check. My question is, although my sister and I are adult children are we entitled to the back pay? If we are entitled will the money be taxed? Thank you for any insight.

Note that is is REALLY NOT a tax question, but rather a LEGAL question. However, since I know the answer, I will post it.

If she WON the benefit, then died, her estate will get the money.

Assuming you and your sister are the only heirs, you will get the money after the estate is probated and all of your mother's debts are satisfied.