Drive for dollars; write yellow letters; or hang bandit signs.  

I at least want to find out what is going on, is there some type of letter or something i could send out?

The lender will help you write a letter documenting this reason.  

Eviction is extremely difficult to achieve.You will need to get copies of your tenants leases and esstopal letters from each tenant before you take ownership.

Also I would want her to sign an acknowledgment letter stating that her fence is not against my will and that she must maintain the fence and land.Also while I have your attention, what should I do if she refuses?

It is very common to use Docusign or Ziplogix Digital Ink to electronically sign purchase contracts even when they are in town.In a few instances a lender or seller may require "wet ink" but that is becoming pretty rare.

Many people have suggested providing a letter with multiple options when renewing a lease (which I have done a few times) with different pricing options depending on the term selected.

I have knocked on the door with no response and left a letter introducing myself to her with no response.

@Joe TwingI recently received a form letter from the MA section 8 office.It states that you must request any increase 60plus days before your annual lease renewal (it specifically said not your inspection date).

But it's a hassle to monitor so I pay now.They would get behind and the city would send me a letter to cut or they will bill me!