If someone violates a material or important part  of an agreement, the other party will generally not be bound by the agreement any longer. In a case like this, if someone does not come to close a real estate or home transaction by the agreed-upon time, the seller can keep the deposit--the deposit's purpose is to hold the property *until* the agreed upon date, not after it; if the deal doesn't close as scheduled, the deposit if forfeited--and relist the property or look for other buyers. Should she contact you again and want to go through with the sale, you may as a practical measure credit the deposit to her, rather than fight with a buyer--but that would be your choice. She has forfeited the deposit if she has not closed by the agreed upon time.