Jane Alderburg was an unassuming woman who worked her job in research and development at Newton Rubber Co. While she normally worked on making bouncy balls even bouncier, one of her jobs involved working on a secret military project producing something called "Kenetic Redistribution Rubber" for use in military-grade body armor. A sudden accident at the lab caused the complex nanomachines used in the process to infuse Jane herself with the kenetic redistribution properties. With these powers, Jane just bounces back from anything that hits her. Now virtually indestructible from the blunt force trauma caused by things like 100 foot falls and bullets, Jane fights crime for no real reason other than to cure her boredom.

The lab accident also left her looking massively pregnant. Fortunately, the city she lives in isn't very observant about such things, so she doesn't really need to disguise it. For crying out loud, they can't even tell that Lady Bounce is just Jane with a little mask on!