feather plucking/ unfertile eggs

Question
i have a pair of kakariki parakeets, they have gone down on eggs twice, both times she has plucked her feathers and both times the eggs have come to nothing, any ideas?

Answer
Hi, Colin.  Thanks for posting!

I need lots more details from you in order to help you with this.

How old are your birds?  What type of diet are they on?  How many eggs are they laying per clutch?  Are they incubating these eggs that they lay?  Do you have a nesting box installed or are they laying on cage bottom or elsewhere?  Where is she plucking her feathers from (what part of her body)?  Are you sure of the sexes of your birds (females can lay infertile eggs without a male)?  Any other birds in the same cage with this pair?

Any other details would be most helpful.

Chrys