An HOA should always be paid by the owner, they own the property and are legally the responsible party.

They may have a separate system or entity that is used for holding properties vs the business itself for legal protection.

If you need financial help, ask under the "Finance, Tax, and Legal" forum.

If after a number of months of reaching out to my borrower with no success, I can then decide to go the LEGAL route.

If you also have any references for a legal service for sending late payment notices, evictions, etc., please share.Thanks!

You have preyed on people who had good faith in you to care for their properties, for their personal health and safety; and instead now live with ongoing health issues, legal fees, and are forced to reside in unsafe conditions.

IRS publications carry exactly zero legal weightb. if we look at the header of this thread

The mortgage is still in here name so she is still responsible for it legally.

My partner and i are ready to purchase and need to be share it is legal to have an STR in these areas and what needs to be done to be legal. 

Definitely consult a real estate attorney in your state to see what your legal options and duties are.