The suprelorin implant is one of the main reasons why most of my flock are still alive. Unfortunately the way we have genetically engineered chickens for laying purposes hasn’t done them any favours for their health and longevity.
Australorps are high production layers so it’s not unusual that she’s having issues especially at the 2 year mark. Maybe you can help her with a calcium supplement for awhile to help with her contractions. The vet might recommend the contraceptive implant to give her a break from laying.