If you're planning to have more babies it will be good to have a real nestbox. It might be easier to buy one than to build one, but in either case you need to plan for how you're going to attach it to the cage. If you build your own, you need to be careful about things like where you put the doorway. This article has some information on the characteristics of a good nestbox:
http://www.littlefeatheredbuddies.com/i ... boxes.htmlIf you want this clutch to be the last one you can manage without a wooden nestbox.