@Saurabh Kukreja I was looking at a property adjacent to one of my existing ones recently.

There are just a few "rules" you have to follow, but it can open the door to many deals that otherwise wouldn't exist. 

The current company just quoted me more than double the existing rate. 

10% return is probably more than what you are going to get on building a new cabin or buying an existing one these days.  

Trying to keep an existing tenant often produces more trouble than it's worth.To answer your original question, you should absolutely give them a deadline and a consequence.

I sent out the notices to the tenants that were on month to month leases because you have to honor existing leases. 1 moved out and 4 stayed.

I’d also be open to joining any pre-existing groups who I can add value to.

Do you have any control over what the existing owner can do to the property?

Instead, maybe you could offer to forgive the existing debt if she moves out within 10 days.

Side tip, if you decide to close without using a agent (not usually a good idea in a new market) then you need to 100% get an inspection (using your own inspector, not the listing agents) and be there during the inspection, title insurance (as always), and have a pre-existing relationship with a property manager.