Thanks for your comments

[busybody]

Our new avairy is 3.6 metres high, 4 metres long and 2 metres wide.
I can set up multiple nesting boxes for them and there is enough room for them to get away from each other.
Can you suggest how many birds would be good for that area?
Both Billie and Millie are avairy birds although Billie did have his wings clipped and was able to come out of this cage, sit on you and started talking before Millie came. Now he will still sit on your hand if you need to move him from cage to cage but is much happier with Millie. When you call him from anywhere in the house, he will answer you where Millie never makes a noise. She leaves it all to Billie. They will talk (in bird talk) to each other. The baby talks to the wild rosellas every morning.
All birds are in an outdoor avairy that is attached to the house. The new avairy is also attached to the house.

[U.S Marine]

That should be big enough, do you breed
them to sell or no?