You do have your numbers solid but searching for the same returns in commercial multifamily will likely lead to failure.  

Philadelphia has some crazy rental regulations, and failure to comply can result in the judge ruling that no back rent is due!

However, in your original post this desire came out of a failure to stay on top of the rapidly growing landlord-tenant laws.

In fact, it could arguably make it worst because the mistakes that many shareholders and members make gets compounded by having to deal with two separate entities (e.g. under-capitalization, failure to adhere to corporate formalities, intermingling funds, etc.). 

The most important thing I did was to boldly experiment with the things I learned & learned from failures & believe me, I failed a LOT!

Can the family evict based on failure to pay?

We also told her that failure to sign and return by a certain date would result in an issuing of 30 days notice. 

You've got to let go of the emotional side of this failure, learn your lesson, and move on.I hope you've found a property manager.

Now, about a decade later, I've learned a lot...I've learned that a "try" is nothing but a prolonged failure!  

Scale, hardwater, well water with sand in it, debris from flushing hot water tanks, debris from dip tube failures in the hot water heater, all play havoc with all modern fixtures.