Release her and find a new tenant before she moves out.  

And you don't have to worry about obtaining a portfolio loan with partial release clauses etc. 

June data was released today regarding the Central Texas housing market and the data trends performed as anticipatedThe The City of Austin saw an increase in median home price from $565,000 to $575,000, n increase of $10,000 from the preceding month and a 42% increase from the previous year.

I would chat with a lawyer first to see what if any documents you need everyone to sign to release you from as much liability as possible. 

Once the garage is repaired, the funds are released to the seller.  

We tried to get the money to buy the home but weren’t able to get enough in time because the starting bid wasn’t released until last night & it was set at $320,000 which was over $100,000 higher than we thought.

 Maybe just offer to only charge "rent" for the number of days between when they signed and when you released them from the lease.

They don't even have an exact date that they release 2nd installments by. 

They have a contract with you, so if they want you to release that contract, they need to return ALL your money.

You can release a person who leaves if you want, but you don't have to until the lease is up.