Investors, markets and strategies are about as varied as anything.

He was the main reason of why I went to college and graduated with a business degree that emphasized real estate.  

I've heard on the BP Podcast (sorry, I can't remember which episode) that Zillow and Trulia buy their data from the same source, and that the values listed on those sites can sometimes vary by orders of magnitude from the comps on MLS. 

I have properties in different states with different ppty mgmt and lease agmts obviously vary, so not sure to what extent these points are already spelled out (if any). 

The "notice" time will vary by locale, google your landlord/tenant laws.

the huge spread was due to updates varying.  

The process can vary by state.When a bank/lender is not paid on the mortgage/loan after a certain amount of time, they will declare a default.

All of a sudden, it became very apparent to what degree these were a luxury, as opposed to a necessity.

Sure it could be a total stinker and you could need to sell within the next 6 months but it would be a valuable lesson learned for way less than a college degree.

Texas laws may vary slightly on this topic from OK so check your property code but this is what I would do:Make a note today that she appears to have moved in.