The tenant also says that I'm harassing her be walking in front of her window.

If the agent is so confident about everything going well, then they can have their commission held back until you get the property in your full possession, fully vacant and in the proper condition you agreed on....... let her $$ be on the line until everything is finished up correctly....The dual agent gets paid no matter how bad it goes for you....they have zero skin in the game after the sale.

Second, I introduced her to the bigger pockets money podcast (the real estate one did not interest her), and that opened the door to her being exposed to FI and stories of successful real estate investing.

Looks like she lied about her being landlord losing his house. 

Cracks like those are normal and so long as the slab is not significantly heaving or sinking, I wouldn't worry about it either.However, does the flooring product require a vapor barrier between the concrete and flooring?

You'll need a vapor barrier and insulation on the garage floor and stem walls.   

No due diligence with non-refundable earnest money.With her being from California, I told her "we don't do that in Texas."

Hypothetically, if you felt sorry for her b/c of the 11mo old baby and wanted to give her a break b/c of that situation, that could be interpreted as discrimination based on familial status - even though it may *feel* like you're trying to do the right thing.Step 1: determine your criteriaStep 2: screen applicantsCould the Mom be a co-signer on the lease? 

Based on your follow up post about her being a chemist and his VA check being 3x monthly rent, my concerns were unfounded.I was partly concerned about this possibly being a common scam.

let her be move on geesh.