Since she is essentially liken to a new tenant that signed for the coming available space by herself, can the landlords hold her accountable for breaking her lease to a property that now has a squatter in it?

They lend in the STR space and may be able to help.

Also if you have to VA loans together, so you and a friends that has VA entitlement then you can get approved for a 6 unit with one commercial space. 

In inflated markets (a condition you can gauge by the increasing gap between asking/offer prices and the prices at which homes APPRAISE) profitability tends to shift away from buy-and-holding turn-key properties to favoring the rehab space of investing, flips and BRRRR. 

I'm local to Nashville and work primarily with investors in the 1-4 unit residential space.

Relationship with wholesalers will come along the way but in this current market inventory is so tight, everything sells (sometimes over market) so the timing is not ideal to target Wholesalers as your only source of deals. 

Cleaned up the property and created a livable space.

Now, just feet from the finish line our appraiser is not getting info back to us in time for our closing...its gonna be tight.

The buckling people are seeing is usually from installing too tight to the wall.

I did do market research, but it was hard to compare as most of the apartments were much larger in living space, had a tiny backyard/patio, and did not have a personal driveway with a security gate.