Excessive egg-laying is very hard on the female Bourkes Parakeet and depletes her calcium.
She becomes weakened, her bones brittle, and she is unable to pass the egg and can become egg-bound.
This is a life-threatening condition and must be taken care of by an avian vet immediately.
An egg-bound Bourkes Parakeet hen may pant, lay down on the bottom of the cage, strain, bob her tail up and down.
Make sure she has plenty of humidity – put her in the bathroom in her cage on the counter and run a hot shower till the room gets steamy.
Put some vegetable oil on her vent.
Give her plenty of calcium and egg food and make sure you have a full spectrum light so she can get the vitamin D she needs to process the calcium.
There are also vitamin D supplements available for birds.
You can gently massage her tummy around the egg too.
The most important thing you need to do is get her to an avian vet asap.