Since they have been living with the fiancee's mother, would she be willing to be a guarantor on the rent?

Johnny pays cheap rent to the owner, which is contributing to the  down payment of the purchase price.The house Johnny lives in  also has a lien on it, because the seller's mother left behind a sizeable nursing home debt. 

I inherited my duplex from my mother and want to create something good for myself with her legacy. 

My situation, I'm a 32 year old single father of an 8 year old girl, I have a full time job making around 61k/year I have been renting a townhouse from my mother for nearly a decade, never really thinking I would have to move in fact, I assumed(like an ***) that I would just end up owning it sooner or later, I never prepared for having to move or prepared a downpayment or anything of that sort, in other words, I've been very stupid over the years.

@William Allen Thanks William for your input on where to look at for the house hacking definitely is my top choice since that’s where my mother is thinking about relocating to. 

.- In Dec 17 there are no visible sign of mold but a mother calls the property manager requesting an air quality test because her son has respiratory problems. - Dec 17 we do the test and it reveals mild elevation (500-1500 ppm) of either Penicillium (laundry room, 1 bedroom) or Cladosporium (bathroom).

@Jessie Huffey I do not pay much rent to my mother, usually $200 a month.

It sounds far and high enough from the ocean, but you never really know what kind of storm mother nature can cook up!

My mother worked there as well in the closing department, Kathy is a top notch person! 

I'm not a single mother though, I will have help from the father (that info plays into my money expenditures).