Hi Hana,
At 6 years old, your Amazons are just now at the age they should be paired up for breeding. In the wild, they would not begin breeding until 5-10 years old. Birds mature more quickly in captivity, but they really are not ready to breed yet. They have more physical and emotional developing to go through. Your 3 year old Amazons should not have been paired or allowed to breed at such a young age. Young females are at a much higher risk of becoming egg bound and dying. And young males are often more interested in mating than helping to care for eggs or chicks. And young pairs in general tend to develop bad breeding habits that ruin them for being good breeders – eating and breaking eggs, not sitting on eggs or not feeding the chicks. I wouldn’t worry about your 6 year old pair. They probably just need more time before they are ready to lay eggs and raise chicks.
Thank you for asking Lafeber,
Brenda