Landlord will not return money given to hold apartment.

Back in April, my wife and I were about to rent a house from a woman. We put a deposit on the house, then weeks later, the landlord had issues getting the current tenant (a friend of hers) to leave on the date everyone agreed to (verbal agreement with email correspondences showing dates agreed to, no lease was signed, was going to be a tenant at will). She notified us that we would have to move in a week after the end of our current lease and offered to return our deposit if we needed to bow out of the deal (have the email where she states this). We told her we could not be homeless for a week before moving in and decided to look elsewhere for an apartment and she agreed to write the check in a three days after a long weekend trip. After a week, she told us the current tenant who refused to leave on time suddenly moved out and nobody is currently living in the apartment. Because she had no tenant, she was now paying two mortgages and had used our deposit to pay the mortgage payment. It is now the end of July (three months of "just a couple of weeks" and "As soon as the house sells...") and we have not received our deposit back. We are still in contact with the landlord, who remains friendly, but she says she simply can not return our deposit until the house sells because she has no money after paying two mortgages (she put it on the market). We can not afford to supplement her mortgage and pay our current rent for however long it takes to sell her house, especially when the deposit is supposed to be kept in a separate account, correct? What can we do? We feel bad that she is in a financial crisis, but this is putting us in a financial crisis because she could not be an effective landlord. Can we do a chargeback on the check we wrote her?