How old is the ten sisters and birds can have eggs

The ten sisters were sexually matured after three months of birth, and then they could be added.This bird's artificial hybrid variety, breeding requires a certain amount of materials to build nests, and usually uses brurders, feathers, etc. as materials.Usually, 5-6 nests can be produced a year, 3-5 of the first nest, and the second nest will increase to about 8.This bird's hatching takes 12 days, and the feathers can grow after 21 days of shell.