Hi Barbara,
Please see my detailed response I posted for you on December 8: https://lafeber.com/pet-birds/questions/parakeet-laid-6-eggs-none-have-hatched/
In short, looking at the calendar, the last egg would be a week past due now, so it’s safe to go ahead and take the eggs and nest box away. Again, assuming she does have a mate, and this is their first try, it is very common for the first clutch to fail. You need to take the nest box away and rest the pair for several months before giving it back to them and letting them try again. Meanwhile, make sure you have them on the right diet as I described before. Breeding birds take a lot of patience and you are likely to go through a lot of disappointment. Some pairs never managed to hatch chicks. All you can do is provide them with a nutritionally balanced diet, the right kind of nest box, and do not let them lay eggs more than 2 times a year, with a 6 months rest in between. With any luck, one of these times they will hatch some chicks!
Thank you for asking Lafeber,
Brenda