The majority of STRs you see for sale or those with lacking design and amenities...and there is a reason. 

Being more affordable than the southeast, allows us to get in with a better basis and potential for growth as more people seek out affordable places to live with strong lifestyle amenities, and convenient travel available: major industries, all major sports, Delta Hub airport."

Commercial multi family is dominated by apartment developments filled with amenities and rents that were the first to reach the top of the market and the first to see rent decreases. 12 unit compares well to 3/4 unit buildings with some operational efficiencies. 

In a C class area, maybe check other comparable properties to see what amenities they have and which properties are getting highest rental rates.

It's a good home, in a growing neighborhood, near college campuses with community amenities. 

For what it's worth, some ideas I've seen pitched are grocery bundles (e.g. a breakfast bundle for 2-4 people with eggs, bacon, bagels, cream cheese, and OJ all pre-stocked in the fridge), meal kits, a pre-stocked drink fridge, charcuterie boards, premium coffee selection, bike/e-bike/scooter/kayak/canoe rentals, video game consoles, upgraded work-from-home office amenities (e.g. oversized computer monitor), etc.I'm not a lawyer, but cocktail kits, bottles of wine, local craft beer, and other alcoholic items seem like they would fall into a grey area from liability perspective. 

It's the lower bedroom counts with limited amenities in the community and low to medium theming that are oversaturated.

If you go the AirBnB route just make sure you go all in - don't skimp on furnishings, design and amenities - so give yourself enough room to purchase these items.

We are a military family active duty to reserve and now looking to enter retirement years, so we see how beneficial it is to be close to the base and those amenities.

Is ac mentioned in her lease as an amenity?