I wouldl say around 30 gallons and up. 30 gallons is too small. An adult bearded dragon should be in an enclosure of approximately 4 feet by 3 feet. The absolute smallest recommended is a 40 gallon...
The female bearded dragon lays her eggs anywhere from 4 to 6 weeks after a successful breeding.
A female will likely lay eggs whether she has been bred or not. They generally lay their eggs sometime...