Not sure I can advise you on that, since it's a family situation. 

I am open to any advise on the matter. 

If you want more advise reach out to @Dmitriy Fomichenko who is the expert in the field.Good Investing...

Then talk to them about what you want in the lease, they can advise you if that is something that is appropriate, or if it is excess or a violation.  

I am not an attorney (advise you talk with one) and this is what can be done in Illinois, Texas might be slightly different. 

Trust me, many lenders will tell you they can do this...but it's very rare to find lenders that know how to advise you on it.

Anderson Business Advisers has a wonderful YouTube page which is more than likely how the OP found them.

I already contacted the post office and they said just put their names on the outside of the mailbox, which is not working Just to add...before renting the units I check with the post office and they advise to put their names on the outside of the mailbox, which I did.In the lease each unit is under same address, but separated as different units such as unit 1, unit 2 etc.. 

It's really hard to know what direction your city council will go in but it's advisable to try to talk to someone in the City planning department to get a read on the council's sentiment and to ensure you are at council meetings where it's going to be discussed. 

Let me know if you have any advise on getting started.