I think it’s worth exploring.

Legal is always the last step to take, but in this one, I would explore it considering the ramifications. 

It seems she was in the "small family" category as the technicians never saw evidence of anything near the volume she was reporting.I did learn the Teriminix $800 house sealing treatment can be had for much less if you get the Home Depot squirt gun and caulk-like sealer, then patiently explore every crack in your foundation. 

It isn't your fault if that's their expectation here, but as landlord it is your duty to explore and understand their point of view if you want to curb the frustration on both sides.Getting maintenance calls nonstop is one of the biggest reasons why owners who are otherwise capable of running their own rentals turn to property management companies.

Also to note: I'm not dead set on Austin - I've also been exploring the San Antonio area as well, which still provides proximity to New Braunsfels/Austin, but you can find triplexes/fourplexes in the metro for under 300k.

To your point, I haven't explored the rents in those places, but it does seem that the rents in the suburbs aren't that much drastically cheaper than the city; only slightly.

I've explored those options as well.

You should explore the 5% down conventional loan if you qualify.

Be patient, explore other neighborhoods and be ready to act when one comes along that meets your criteria. 

I would suggest exploring the networking tab here on BP.