So if you can find a suitable property management agency, it will help a lot.

I do have appropriate protections (a diligence period where I have the right to terminate if the property isn’t suitable)

I’m located in Pittsburgh, there are not many if any multi family properties in my price range OR in suitable conditions to withstand a VA appraisal.

I would guess they might be long-term tenants given that it's hard to find suitable SF housing.Would you consider this prospect? 

If not familiar, go to your local real estate attorney to find a suitable commercial broker.

You can't just change the terms of her lease unless she agrees as well.I'd say to her, "apparently you aren't happy here, so if you would like to find a more suitable place, I'll let you break your lease with no penalty".She's done a pretty good job of getting you trained and if you don't put a stop to it, it will only get worse.

If it was a visitor, it was their visitor.

The visitor clause is really for family or friends who may travel to visit.

Not every property is suitable as a cash flowing rental.

Four bedrooms are great for families and visitors who will be staying a full season and for the guests who show-up during that time.