Cities and communities are also cracking down on people using homes for this.

She will probably game the system for the next 6-12 months, but that's what you get buying a property with a non-paying tenant in place, in an anti-landlord city. 

Quote from @Ryan Brown: Your city has noise ordinances.

Quick question: What’s been your biggest challenge when managing smaller multifamily properties?

Like "Biggest single family propetry management mistakes ever" etc

But in my opinion, the biggest issue I see with folks jumping into their first "big" multifamily deal is the quality of the pro forma. 

Create columns for Name, Street Address, City, State, Zip and then contact info: Last Contact, Relationship, Status, Email & Phone.IMPORTANT: do NOT ask people for THEIR business, ask for referrals!

I have a great one in Kansas City for over 15 years that I've used multiple times (only auto loans however), but hoping to branch out locally as I begin my investor journey in Arizona. 

The city has been trying to decrease density in areas it wants gentrified for a long time. 

City won't let you rent out basement, but owner can live in basement.It may suck for 1-2 years, but then you'll have gained so much knowledge you can do better on the next one!