If the loan is valid and was not paid, the balance due under the loan contract is owed.
It's not clear why this is your problem - why not simply pass the bill along to your family member, the borrower? The borrower is free to try to negotiate a payment plan, or to propose a lump sum pay-off that would be accepted as full satisfaction of the debt. From what you've told us there is no limitations period on the debt, but if the borrower wants that analyzed he should discuss the details of the loan with a lawyer in his state.

