SSI benefits

We are in the process of adopting our fd who has lived with us for over a year. Her mom agreed to TPR last month but the judge still hasn't issued her official ruling as of yet (any day now). During the time she lived with us bio-mom applied for SSI for fd. We had reservations about bio-mom doing it, but had no choice in the matter and took fd to all of the appointments with the doctors over the last year to see if she is going to qualify. Last week we received a phone call stating that her SSI worker was looking for bio-mom and that fd was going to receive SSI benefits. My question is, since bio-mom applied for the benefits and the TPR isn't completely official yet will bio-mom receive the "back pay" lump sum? Her SSI worker couldn't give me any information beyond needing info about where bio-mom was and fd's social worker still hasn't responded to my phone calls or emails. My husband and I are concerned as we feel bio-mom will use the money for all the wrong things and not put it towards fd's care like it should be.