Critique backed up with explanation is gold for me to learn from.So when I say a little slow but never late, I mean that she does not proactively pay on or before the 1st, but she also does not go late after the 5th.

Is there some other explanation that I'm missing?

@Sudhanshu Singha Thank you, I appreciate your explanation.

But, no need to go into a huge explanation. 

The only explanation I can think of is that the offences are all old.

It may have been due to a poor explanation, so let me clarify.

However, I would be responsible for sending you a text/email/voicemail, depending on your preferred method, with a detailed explanation as to what happened.2)It is imperative that as an owner/investor you specify in your agreements that if the repair (non-emergency) is over X amount of $$$,  the PM is required to submit proposals that are identical in scope and that only you, as the investor, can choose the contractor.  

We typically require at least 600 or more, otherwise, an explanation letter is required for any collections and we often make exceptions for medical bills and student loans.  

Many times I have seen folks live in squalor who appear bright and able bodied but their mindset and negative self talk prevents them from ever improving their lives Case in point ; I have some rentals that are on the bad side of town , the buildings are old and probably need some work and oddly enough I get the same $ rates or better than the good side of town that is a far nicer condition property in a better area . the only logical explanation is the tenants choose a “ rough” area to live because they look at themselves as being “ rough” they lived in “ rough” areas all their lives and they know they wouldn’t fit in there I guess . 

Letter of introduction, with explanation that lease increase will be $$$ range come renewal time and you would be open to 60 day notice and would let them out of lease with that.