Is my budgie ready to lay her eggs?

My female budgie is spending most of her time in the nesting box, but she has been spending time in it for quite a long time. I believe she was doing it for the sole purpose of alleviating her arthritis pain, which she has in both of her feet. But I have recently seen her mating quite a bit the past few days, and the male has been regurgitating to her. I am checking the nesting box every 5 hours or so, and she is pulling out her flight feathers, but there are no eggs yet. It has only been about a day and a half since I first saw them mating, and they continue to mate as I speak. Her cere is very flaky, but it has been flaky ever since I got her. The last time she came out of the nesting box [about 2 minutes ago] the area under her tail seemed a bit enlarged, and the male and female mated again. Will they continue to mate even after she is ready to lay the eggs, or even after she has laid them?