Parakeet eggs typically hatch after about 18 days of incubation. It's not unusual for parakeets to lay infertile eggs. I have female parakeets and they lay eggs occasionally, and the eggs would not hatch of course because I had no male parakeets.
In my case I would remove the egg and the parakeet would go on with life, until the mood struck them eventually to lay another egg somewhere down the road.
When did your parakeet first lay these eggs? Is it her first time laying a clutch?
Lisa Shea, Owner