I guarantee your life would be so much better if you removed her and replaced her with a good renter.Do yourself a favor: buy "Every Landlord's Legal Guide" by NOLO.

Suppose you buy a $700,000 three-flat in Avondale with a $5,000/month mortgage and rent out two units for $1,500 each.

Glad you introduced yourself.. have you identified any mentors who can guide you on your journey?

This will help guide your decision opposed to investing somewhere for a novel reason.for example for me it was cash flow, price to rent ratio, land lord tenant laws and availability of multi-families(Just to name a few). 

Are you looking for guide and advise of an expert on the market or a pass through agen?

.: Here's a good guide with links to the law: https://www.tenantresourcecenter.org/earnest_moneyIf you charge $25 and the credit screening costs $10, you can keep the $10 as income.

You need to learn how to analyze property and determine if they are a good investment.Here's a guide that describes how to analyze a property.https://www.biggerpockets.com/blog/rental-property-cash-flow...

That being said, I don't have the information I would need to say for certain, but that sounds as if that's a high price for the asset you're considering to buy.

I’m looking into buying a rental(s) in this area.

As others have alluded to, buying larger units or a house near the beach is a better play.