A duck laid her eggs in my garden 3 days ago and hasn't been back. Help!?

[B G]

Last June a duck (Daisy) laid her eggs in my garden and we helped protect her until they hatched. She came back and laid them in the exact same spot but has dissapered. It has to be her no doubt but she is early this year and she was late last year. I don't know what to do if she doesn't come back. It's been 3 days since she buried them with no Daisy in sight. Help!