Owner Financing Park Owned Home--to current renter

I own a park and most of the homes in it. I have been owner financing all of them as I turnover renters. So far, going well. Here is my question. A renter, who has been in place for 1 year and 3 months approached me about buying the 3 x 1 she is currently in. She can come only come up with $500 down. I have been getting $1000-$1500 on comparable homes. The good thing is when she moved in, I only spent $525 on turning the unit over. No paint or carpet. Just general cleanup, new stove, misc. items and a few electrical bills. Her current rent is $395 with lot rent included. I am leaning toward doing a 10 yr. am schedule keeping the payments the same as they are now, with 500 down. What do you think?