It very well may be a new couple, or papa may have a new mate – I would almost bet this is the case, since they were gone so long. If this is the case, don’t believe she would lay eggs in a nest she did not build. I had the similar situation this past week – I believe my regular mama of 5 eggs went MIA also, probably got killed or died. Nest was not touched, so I believe something got her. Papa found new mate – & they were very much “in the mood” with all the wing-waving going on. But she never did nest/lay eggs anywhere (I don’t believe). I removed the eggs from old nest after a week and being positive they were no good (put dots on top & were not being rotated & no one going in box at all). I left the nest in for a few days, but was told here that a new female will usually not build or lay in another bird’s nest. So I removed it, and this pair is definitely interested now.
In your situation I believe I would wait a while to see what happens.
