Hi,
All you need to do is take the nest box away. They only need a nest box for breeding – it should never be left up year round. If she doesn’t have a mate, then she should not have a nest box at all, even if she lays eggs. In the wild, a nest is only used once a year during breeding season, then they abandon it until the next breeding season a year later. In captivity, they do not get the signals from nature to stop breeding, so you have to remove the nest box. And again, unless she has a male mate, she should not have a nest box. So remove it permanently if it is just her, or if she has a mate, remove it and don’t give it back unless you want them to breed. She does not need any type of nest, bird hut, tent, box or anything else to sleep in. Birds do not sleep in nests in the wild, they sleep high up in trees. So put a high perch in the cage for her instead of the nest box.
Thank you for asking Lafeber,
Brenda