Ok...here is a lot of info that i hope will help.
I have bred and raised tiel chicks in the past so know a bit about it.
Your female tiel
will produce eggs and even more so because she has a male housed with her.
Female cockatiels produce eggs even without a male present but will
want to reproduce even more (instinct) with a male present during the
breeding season.
They will eventually end up mating and she will lay eggs and sit on them whether they are fertile or not. She will take turns with the male sitting on them if you keep the male with her.
*Note.....If the eggs are
taken away one by one each time she lays one b/c you do not want them to have babies she will make
more eggs over and over again because of the male present and the instinct to reproduce...
this is dangerous to the female. Do not do this!
She could get what is called egg binding due to loss of calcium from producing eggs over and over again. Egg binding and continuos replacement of eggs on the females part can be fatal and is more often than not The females body loses too much calcium and it ends up fatigueing her and she gets weak and dies. With egg binding the eggshell is not developed hard enough due to lack of calcium in her body and the eggshell is too soft making it difficult or impossible for her to push it out. This will kill her if she does not get help from her owner or is not taken to an
avian vet quickly.
For that reason any eggs she lays should be left there for her to sit on.
But if the male is allowed to also sit on them (continue to share a cage) and they are fertile they will likely hatch chicks.
I keep males and females separate so that if or when the females lay eggs they will sit on them but they will not hatch b/c they will be infertile,...she needs a male to have fertile eggs and to help her keep eggs warm to hatch them
...Eventually she tires of them or enough time will have passed to be safe to take the eggs away. That way she has enough time to build up more calcium for the next clutch...next round of egg laying and it will not be dangerous for her to do so.
To discourage egg laying you can buy dummy eggs and place them in her cage to replace any real eggs she lays. She will think they are hers.They can be left there all season.
If you keep them together and do not want them to breed DO NOT buy a nestbox as this will only encourage breeding. Even without a nestbox she will lay eggs on the bottom of the cage but you can replace them with the dummy eggs so that she will think they are hers and not try to replace the real ones that were takenn away.
So its up to the owner as to what they want to do with a pair of birds. There is a very great possiblity they will mate if they are left together and if that happens hopefully that owner is prepared and has done research as to what do next.
Housing males and females together can create situations not anticipated. Its best to be very prepared if one decides on keeping males and females together.
I know thats a lot of info.
Wishing you the best with your beautiful tiels!
You can PM me with any questions concerning your tiels that you might have.