My brother technically owns the property, but my mother & aunt currently lives there.

I am currently renovating my SFH with a mother-in-law apartment in Salt Lake City, Utah.

There are similar houses with connected mother-in-law suites and what not, but not exactly the same situation.

My mother wants to keep the house and my father is willing to accept cash in exchange for his share in the property.

My mother is going through something very similar right now.

Based on some quick research, the value per square foot in my area is around $700/sqft and it looks like I've got about 1000 sqft below me that could be reasonably dug out and converted into an awesome mother-in-law.

My mother in law recently passed away.

The Mobile Home Park was left to the owner by her mother and the current owner has decided that she does not want it anymore. 

This is located half mile away from a house I own (my mother lives in it) as well as my first rental so this would be my third purchase within the area.

Its actually because the mother in law unit is connected to the main unit.