I grew up with rosellas, the first we had died at 23 and his partner a few years later with 20. We were devastated when they passed away. But after year we got two new 1 1/2 at saturday and i never noticed how much i missed their colorful feathers and chirping.
The males are a bit taller than the females and the white spot on the neck is bigger. So i would say the more red one is the female and the more colorful one is the male