Gut call the bank first thing on Mon and ask what all needs to be done beside the assessment. Ask your realtor to call the title company and see if you can get a copy of the search or commitment/binder and see if that shows anything that needs to be cleared up from the previous owner that might be holding up on the sale on the seller's end (they may not give you a copy, but they may give your realtor a rundown of where THEY are in the process and that will help). Just because a loan is scheduled to close in 2 weeks doesn't mean they have to cancel it now. They can get this stuff done, but it sounds as if the woman is too lazy to do it. AND, the closing date can be extended. It's done ALL THE TIME. But THIS is what your realtor is being paid a commission for, to help with things between you, the bank and the title company so enlist his help.
I have a good feeling that this will go through, but sometimes you have to really stay on the people doing the work to ensure it does. It's no skin off their back if it doesn't, they have a house to live in. But I think that many times, people in this business forget they are dealing with real people and their lives and homes and just look at the numbers instead or don't want to do what it takes to make the loan happen.