[FaeryBee]

How old is the youngest chick?
Have the other four chicks been fully weaned?

Remove the MOTHER from the cage and put her in a cage by herself. She should have been moved out as soon as the youngest chick was 3 1/2 weeks old.

All the chicks that are fully weaned should be put into a cage by THEMSELVES.

The only chick(s) that should be left in the cage with the Father at this point in time are any that are still being fed by the Father.

As soon as the youngest chick is weaned, REMOVE the nest box from the cage.
You should not be breeding any of your budgies from here on out.

When all the chicks are fledged and weaned, then you should separate all the females into one cage and all the males into a different cage.
How many females are there in total and how many males?

 

[FaeryBee]

Please read my response prior to your last post.

 

[FaeryBee]

Yes, siblings will breed with one another as well as with their parents. That is why I'm recommending you separate the budgies by gender.
Once we know how many of each gender you have, then we can give you advice with regard to the size cages needed.

You'll have to see if the Mother can get along with the other females before putting her with them. If not, then keep her caged by herself for awhile longer.
The father should be housed with the male chicks.