Probably not – it depends on how many eggs there are. But most importantly, you need to remove one of the males and females. You can’t breed cockatiels this way, as you are finding out. You can only have one pair in a cage if you are breeding them. Cockatiels are very territorial and will kill each other over a mate or nest box. What is going to end up happening next is the females will fight over the box, and most likely all of the eggs will get destroyed. Or if any chicks hatch, they will end up getting killed unless you remove one pair of birds. If you know how to candle the eggs, I would take out the new eggs, and the female that laid them along with one of the males, and move them to another cage with a new nest box. Then maybe the other hen will go back to her eggs. But you need to keep the male who fertilized the eggs with her, because both the male and female take turns sitting on the eggs. Then there is a slight chance that the eggs might hatch. I doubt this is going to turn out well, but you must remove one pair of birds to avoid disaster here. You can’t leave two clutches of eggs with one hen. If they did all hatch, there would be too much of an age difference between the first to hatch and the last to hatch – it could be two weeks or more depending on how many eggs there are since they hatch every other day, just as they were laid. If none of the eggs are fertile, then you still need to separate a pair, do not give either pair a nest box and rest both pairs for 6 months. Then you can return the boxes and let each pair nest in their own cage. You can’t allow them to nest over and over. They must be rested for 6 months between each clutch of eggs, whether the eggs hatch or not. They should only have 2 clutches per year – in the wild they only have one. I would recommend looking through the past questions here about breeding cockatiels so you can know what to do, because the first rule of breeding cockatiels is to only have one pair per cage. If for some reason you can’t get another cage to separate a pair, then remove the nest box and do not give them a nest box as long as you have more than one pair in the cage.
Thank you for asking Lafeber,