The male (Boy) parakeets have a BLUE nose/cere (right above the beak)
and females have a PINK or BROWN nose/cere, and babies are white, purple or in between so you will not be a ble to tell until they are older. you can google it just tipe in "Pictures of male parakeet" and when that comes up google "female parakeet pictures" and you should see what they look like