Questions about old MAP with Freddie Mac

I hope someone can help me out on this. My daughter-in-law purchased a house in 2004 with a Mortgage Assistance Program 0% loan of $23k. It was run by Freddie Mac at the time. They are planning to move to CA now and want to rent out the house. Unfortunately the contract says that payment is due if you rent it out and we have been unable to find out if it is due in full like a balloon or if they can make payments. Things have changed so much with the mortgage situation since then, we are really confused about how this would work. They live in Maryland now, so if anyone has any info about how to check on this and find out what they need to do, I would really appreciate it. Thanks so much…Jenny