She didn't quite make it to the Front, but it wasn't for lack of trying.
Maude Butler was turned down as a Red Cross nurse when she applied during the First World War - so she acquired an army uniform and stowed away on a troop ship from Australia to Egypt. What gave her away, in the end, was the fact she had not been able to get the right boots - she was wearing her own boots - and that she needed to raid the ship's kitchen for food.
She was sent back to Australia on another troop carrier.
She was only sixteen at the time.
She did get to become a nurse, though, and ran a private hospital later in her life.