Behaviour and next steps
Thank you for quickly answering my question about my bird not wanting to hatch her eggs. I did remove the box and the egg as suggested.
Currently the male who mated does get a little protective and ocassionally attacks the single male bird. But the single male bird is not attracted to the female one, but shows a lot of affection and drops hints being attracted to me and shares a very special bond with me. The pair that mated are the ones that I rescued and am not sure of their age, they look young and small though and I dont have access to show them to any vet here.
As far as petting is concerned, the pair does not let me pet them, but they feel free to come and sit on my head or shoulder or eat food from my hand, I have the pair since about 6 months and the single bird for almost 2 years now. The single bird lets me scratch him on the head and neck and looks forward to spending a lot of time with me everyday.
I would greatly appreciate if you could give me some tips on how to manage these 3 in the same cage.
P.S. none of them enjoys fresh food on a regular basis, I give them brocolli, spinach, carrots, french beans, capsicum, sprouts, cooked lentils and boiled white rice. They rarely eat the fresh veggies and enjoy eating only cooked rice and the grains on a daily basis. And none of them even attempts to eat any fruit.