Tenant moves out on X date and they pay a set lease break fee.

Here at work is where I post on internet forums, because I have time. 

Ask her to sign a new lease, making the 23rd the new date of paypment and the new beginning of the month.

Because when you give them the "right" to do so, including a time frame within which the settlement date can be considerably delayed, tenants who actually have zero intention of purchasing can take advantage of the situation and squeeze the seller out of a portion of their sales proceeds through a negotiated waiver or assignment of their "rights". 

Agree mostly with @Yoann DoratIn our opinion, you can do Class C remotely, it's not easy, but NOT Class D.80%+ of property management can be done from anywhere you can get an internet connection - once you set up the proper systems. 

Maybe you want to pay interest when you sell and on some deals you will pay internet monthly (for a lower rate)...many possibilities. 

The buyer and I signed a contract back in May for the sell with an expected closing date of June 18.

We would determine a date for a balloon payment where I would refinance the property into my name.

As you know where she lives you can word if she wants anything to come pick it up by X date.  

It costs more so may or may not be the best value if styles change and the floor looks dated in 10 years.