Renters interestd in my house under the right of TOPA

[Jun Shi]

I have a condo in washington DC and was rented to this tenant since August 1, 2017.  I wrote her a vacant notice on May 2nd to inform her that I was going to sell the condo and would no longer renew the lease after July 31, 2018.   

She moved out on July 31, 2018. I put the house on the market around middle August,  and sent her a TOPA notice. I got a good offer from a third party around the end of August. We did not receive the TOPA from the tenant until two days ago , and she claimed she would like to buy my condo.  I know she has no intention to buy this unit at all. All she wants to do is to get some profit from her right. 

I consulted my escrow & title company. They told me since in May , in my vacant notice i mentioned i was going to sell this condo , i should still comply with the old TOPA law. In other word, unless she waived the right, i still have to sell the condo to her. 

Now i have two qustions to ask here . 

(1) Is my escrow company's statement correct?  As we know , if under the new TOPA law, i will be exempt from TOPA. So which law should applied to me is decided by my intention date to sell ? It is not decided by the date i signed the listing agreement with the agent which is aound middle August? ( new TOPA takes effective since July 3rd)

(2) If i cancel the current offer deal, and keep renting this condo to another clients, can I just get rid of the TOPA right from the pervious tenant? If I can, how long at least should the new lease be?   Can i sign a short term lease like 1 or 2 weeks?