Welcome to the forums!
In order to breed responsibly and be fully prepared for the journey and everything that it entails, a person should have a very good grasp of the species and in this specific case a decent amount of real life experience in budgie ownership, this coupled with the necessary research into the subject will raise the chances of success.
The decision to breed comes with a whole lot of responsibility and commitment, the lives of the breeding pair(s) and the chicks are depending on you and the response you give if/when faced with adversity.
Things like being able to tell if your breeding pair is in good health and top physical condition to go through breeding; when a hen is expecting an egg or if she is showing the first signs of being egg bound; when a chick is having developmental problems, not being fed or showing signs of dehydration;
when there is aggression, abandonment and neglect of the chicks and it's solely up to you to feed and raise the chicks. The ability to detect early on and solve these issues can truly make a difference on the outcome of your breeding journey.
Please check this link: https://talkbudgies.com/budgie-breedi...s-new-old.html
Now onto your queries, from your description it does seem that your budgie is carrying eggs. If during the fall your hen has hit the vent area then it's possible she may have seriously hurt herself and if the currently formed egg has broken inside of her, then her life is truly at risk and she would need emergency medical attention.
How is she coping now? Does she seem to be in pain or distress?
Do you know the signs of an egg bound hen?