Typically with owner financing they will want 20% down to protect themselves and make sure you have skin in the game.You could propose it but just wanted to let you know that this is not a very strong offer. 

Cash offers would net you less.  

Houses are pretty cheap and can offer good cash flow.

She is offering to refinance one of her homes that is completely paid off.

Any contract or suggestion they give seems overpriced, whereas contracts/work I've found seems to be much more reasonable. 

Be sure to explore all around the forums as well as many of the FREE tools that Bigger Pockets provides.I am on the lending side of things and am always happy to hop on a call to discuss loan options that are out there, even if not offered by my resources.

You could offer seller financing (preferably with 20%+ downpayment).

For instance, I'm a veteran and do a lot of VA loans and one bank I work with offers the same rate to veterans with a 685 credit score as they offer for veterans with a 758 credit score.

I would also ask them about cash for keys since I would initially offer the tenant this. 

.: Application/Screen every tenantIMO I wouldn't allow pets since it wasn't leased with petsOtherwise a non refundable pet feeI would charge at minimum 350 upfront per pet or not allow them at allThe Realtor who sold me the property and helps me find tenants, suggested $500 nonrefundable deposit for 2 cats and $25 a month each.