Mockingbird eggs..?

I found a mockingbird nest with 6 eggs that had to be moved from an old car , so I put on the fence next to the car. The mother was not coming back to eggs / could not find the nest , so do not know what to do! I contacted two nearby wildlife Rooms have said to leave the eggs for another animal to eat , is that the only option ? ! This is time sensitive , so I want to know ! Currently I have the eggs nestled in a sock full of rice to negotiate with another every 30 minutes. They have been inside / motherless for a little over an hour .