Over 4 mortgages, the lender will require six months of “reserves,” the principal, interest, taxes and insurance, plus HOA fees for each house.  

You also need errors and omissions insurance, mls access fees, local association fees, state and national fees, continuing education costs, among other costs.

I don't know that area, but $24,000 a year for insurance seems really high.

The stock market plays a role, in that it is people's perception of the health of the economy and some people will use stock market profits to fund a real estate purchase.

Maybe temp insurance?

The agent said I can’t get builders insurance bc I have to assure them work starts 30 days from closing.

The title company will find all liens on the property in order to give title insurance.

Build your reserves first - 6 months of mortgage, taxes and insurance.2.

She's been dealing with various health issues that have made paying rent on time a problem.

There are two exceptions: Nonqualified use does not include any period of such use that occurs :(1) any time during the five-year period ending on the date of sale that occurs after the last day of use as a principal residence, or [ Meaning, of last  5 years, if you  rented a property of last 3 years does not trigger non qualified use, but in the last 5 years, if you first rent for 3 years and then move in for two years as a primary residence, 2/ 5 years is non qualified.](2) any time (up to two years) that the taxpayer is temporarily absent due to change in place of employment, health, or unforeseen circumstances.