Why does your conure have a nest box? Unless you have a pair and want to breed, a nest box will only confuse your bird.
Birds bodies get ready to breed (lay or fertilize eggs) when their environment looks good for raising a family. So, long hours of daylight, rich food, excessive stroking or petting, and presence of a NEST are enough to start an adult female parrot laying eggs. This is hard on her body and dangerous as the eggs can get stuck if she lays many of them.
I didn’t see anything about a male bird or wanting to breed them. If she’s alone you need to take away the nest box. As you see, besides laying eggs, being in breeding condition makes her not such a good pet.