Your Realtor should be able to reach the previous listing agent and explore what the seller's plans are. Once that has been done, have your Realtor contact the seller via public records or the information on the expired listing if any. Usually you can find the seller and at last resort you could write to them at the property address and hope it is forwarded.
her number is
Tierra Antigua Realty
If that agent doesn't have any interest in working with the seller, but would share how to reach them, it would be nice for your agent to send them a referral fee for their trouble. It will give your agent a good relationship for future business and the good will would be great for you and your life.
I wish you well in this transaction and hope the seller still owns the home and is willing to sell now that you are ready to buy. Merry Christmas!