And we certainly have a laying worker, since there are multiple cells with multiple eggs.
Multiple eggs in a cell is not exclusive to a laying worker. Young queens often lay mutliple eggs per cell. I guess it could happen to a queen later in life too. Perhaps that is why they are trying to supercede her.
I had one queen this spring that was laying 3 eggs in each cell, when I checked back in a few weeks, she was fine. She was a Fall queen last year, that was fine then too.
Which ever it is (laying worker/failing queen), you must get rid of her before introducing your new queen, otherwise the new queen will be killed.