Green Wing Pair/ Has Half developed embryo.

Question
We have Pair Green Wings.They are older we adopted from an a lady who was in her eighties. And just could not care for any more. We have had them several 3 yrs now.
They started getting real comfortable here We moved them in a double Macaw Cage from there previous Very small Round cage.She started to Lay eggs on the bottom of Cage Repeatedly. So we got them a breeder box they started Making comedations right away.
She Lays Three each time. 1 out of the three usually be fertile  after 30 days i pull them.But each time it was only half developed.They eat pellets fruit mix Garden mix,I give them real fruit every 2 to 3 days They have unsalted peanuts almond, walnuts when i can find them.
Brazil nuts,they getmissing link powder in ther pellets bowl.Fresh water mixed with acidophoulas Drops, Calcium drops I alternate 2 or 3 xs a week.They get corn on the cob,peas, green beans. Bread  sometimes eggo waffles, He loves blue berries, cherries,black berries.
They have there uv lights on top of cage. Showers agian i try 3xs a week.
I mist spray her when she is sitting only. Every now and then when she comes out of the box.
She sits real good and he is a doting hubby, pationtly. She wants to try and be a mommy i do not know what or why  they are just half embryos.
They have good droppings i watch carefully for any trouble.They have been to the vet and were checked when we brought them home blood tested and had a clean bill of health.
I am sorry for such a long list here.But am trying to cover everything i can think of.
Can you help with any info or who else to ask?

Thank you
  Teresa

Answer
Let's try to start from the beginning and give them a break from laying and nesting for a few months.  

I'd like to see them off the food additives, which can sometimes cause more problems than they help resolve.  You're doing a wonderful job with the pellets and berries.  
 Add some whole grains every day, and most importantly, dark colored leafy greens like kale, chard, spinach, brussel sprouts.  Get some sweet potatoes or yams into their diet, fresh and cooked carrots, carrot tops and don't forget the cuttlebone and mineral block in the cage.

 I've got a big outline of ideal foods at my site so take a look and let me know about any questions you might have with regard to this  www.4AnimalCare.org  (click on the bird tab).

  I'd rather you offer them some natural yogurt rather than drops in their water which don't usually have live cultures and are a total waste of money - only making the seller rich.

 A clutch of three is usual, though only two generally survive in good conditions.  In "ideal" conditions, all three might make it.
 
Get back to me after you take a look at the nutritional options I've got listed on my site ok?  It's all free, no ulterior motives, it's just too much to list here.

 www.4AnimalCare.org