Some birds do not make good breeders. Your female is old enough, but maybe she is not used to the new home yet. You need to be feeding a nutritionally balanced diet like pellets as well as cooked eggs, chopped veggies and fruits and multi grain bread. If you only feed seed, this is not enough nutrition. Breeding takes a lot of patience, so just keep observing them and hopefully she will lay eggs soon. If not, I would remove the nest box for a few months and try again after that. If still no eggs, then there is probably an issue with her that keeps her from producing eggs.
Thank you for asking Lafeber,