Honestly, it isn't that weird. Social Security can really only hold the father responsible, and it sounds like he is broke and in prison. SSA can only refer it for a fraud case or post an overpayment (debt) to the father's record. If the prosecutor doesn't choose to pick up the fraud case, then that leaves an overpayment posting as the only option. Overpayments can be considered federal debt, but if the father has no income to garnish, they can't really collect on it.

The good news is that overpayments don't go away after a certain amount of time, so if he ever files for any type of Social Security benefit for himself in the future, they can and will withhold benefits to recover what he owes. Anything they are able to get back would be released to Rose's current representative payee (presumably OP). Also, if he gets out of prison, they can potentially garnish wages or take federal tax returns.