Hi,
Does the budgie have a male mate? If not, then the bird doesn’t need to sit on the eggs because the eggs can’t be fertile, and she should not have a nest box. If she does have a mate, you should not be allowing other birds to be around them. Breeding budgies can get very territorial and the females can be especially vicious. They will kill rival females, and rival females will raid the nest and destroy the eggs or kill the chicks. Now that the nest has been disturbed by another female, she may not go back to sit on the eggs again. If she stayed off them long enough for them to get cold, then the eggs won’t be good anymore. Again, if this is a breeding pair, move them to another room where the other budgies can’t get to them. A breeding pair needs privacy and will not tolerate other birds coming around the cage or nest. If they get too nervous, they will abandon the nest and eggs.
Thank you for asking Lafeber,
Brenda