Not revealing that rent is late, it really may be a matter of health or well being, based their relationship with tenant you may find out what you need to know. 

I have tenants who just moved into my condo and are requesting compensation for: (1) repainting (I had to repaint a wall in a different color than they originally saw when I took down my speakers); (2) loud bathroom fans in each bathroom; (3) Ceiling fans that are outdated but functional; (4) wall wiring so that their t.v. does not reveal the wires; (5) fridge filter which admittedly was old and they noted that my flooring has a soft spot but did not request replacement (yet!).  

agree with @Steven Sager, do what you can, show that you you are making an attempt to resolve the problem, this will help if you are sued too. one of the problems in this situation that i think is being overlooked is that she was Assigned this spot by the owner, she has no choice but to park there, so some attempt at removal of the problem should be shown and will help with the tenant but explain to them too that the town will not let you remove the tree. but i wouldn't go all out for the tenant, remember she did rent this place knowing she would be parking outside too ( just not under the tree maybe ) I suggest you reveal that to the next tenant that moves into that spot and have them sign something knowing where they are parking.

Giving advice on a deal when not all aspects are revealed is careless.

I just think this seller can't sell it because of something the inspections are revealing.

We were in the process of buying a new home until the final inspection revealed serious structural damages not seen by our first inspection.

In other places, it may even reveal enroachments.At least go as far as having the property lines verified and stake up some strings to show where the fence would go.That should send a message, I think...David J Dachtera

An hoest ten a bit will reveal any blemishes (bk, student loan default, medical collection) that you can verify which will add a few "credibility points" with me if I'm going to consider them.

Open up the floor registers and clean them out, this is not only good for your HVAC system, but also will reveal things like cigarette butts (unauthorized smoking), pet food (unauthorized pets), and the occasional kid toy (this is okay, since finding a barbie shoe or the missing lego will make a child happy.) 3.

Another lesson learned from this experience is to list some specific conditions in my lease, like that pest control is the tenant's responsibility if it's not HOA-related and that service calls for issues that are revealed to be the tenant's fault will be charged to the tenant's account.