Thanks for using JustAnswer.com, I'm Dr. Dan and I'll try to help you.
Not all female greys will lay eggs. The egg laying cycle and the triggers are very complicated and unpredictable. Each bird interprets hormones, environmental conditions, relationship with their owners, relationships with other birds and food stuffs differently. That "interpretation" is what triggers a bird to lay eggs or not. I have seen birds of all ages and types lay eggs at different ages, I've seen proven females never lay eggs. It is not necessarily a problem as long as your bird is otherwise acting and eating fine. I hope this helps, best wishes.