Take ownership of your mistake and learn to do the proper due diligence recommended above😊

They can be purchased at Home Depot or Lowes and installed easily. https://www.lowes.com/pl/Maax-...

If you don't find one and you see a 4" line going int the basement floor than you have a chance of installing a conventional toilet close to this pipe but still a few inches above for proper drain. 

However, you need to find a good life insurance agent who understands how to properly set up these kind of policies.

I would do framed install for something higher end.

There are proper procedures to follow if she decides to withhold rent. ( repair and deduct). 

And yes you need a permit to do anything except the smallest repair.....heck you need a permit to install a new water heater now.

@Andrew Hamlett, your first suggestion could work with a proper JV agreement drawn up by an attorney.

I would definitely talk to an LLC attorney to make sure I'm properly covered.

First of all, I am sure there are some key learning opportunities you took away on properly vetting tenants and figuring out the Chicago Landlord-tenant ordinance (i.e, move-in fee).I'd just talk to your tenant first and see if he can be reasonable, then resort to cash for keys.