Her retirement income would be used to cover the mortgage.I hope this gives you an idea of my plan.

Insurance would cover it, I would pay the deductible, and no assets would be lost.If you are in an area like San Diego where people are more likely to sue, a judge is more likely to find you guilty, and the payout is expected to be higher, you may consider an umbrella insurance policy.

Does renters insurance cover something like this?  

Not every state or city mandates that any landlord has to accept Section 8, because the landlord has to not only subject their property to Section 8 inspections, rules and regulations, they also often have to separately arrange for the tenant to pay the non-covered part of the rent and can face difficulty evicting just based on that.

Have you gotten pre-approved with a lender? 

The process is very involved as you'll have to navigate pre-construction activities that involve architectural plans and approval from the city and then the construction activities (Shovel to soil) take anywhere from 5-9 months depending on how much your building. 

Moreover, can you clarify if the complex is already an existing 16-unit or do you intend to build it?   

Can try to reposition to Class B, but neighborhood may impede these efforts.Vacancy Est: Historically 10%, but 15-20% should be used to also cover tenant nonpayment, eviction costs & damages.Tenant Pool: majority will have FICO scores of 560-620 (approaching 22% probability of default), many blemishes, but should have no evictions in last 2 years.

I would venture a guess that many investors believe that agents who cover the same territory are competitors, however as I'm sure you are aware that there is more success in collaboration as agents than competition.

They might not even cover it if they know it is a rental.