I just got a new English budgie and I got one breeder telling me its a girl and another breeder telling me it's a boy because that specific mutation allows for different cere colors, so I'm a little confused now. The cere is pretty pale in the middle like a girl, but the edges up close are darker purple, like a male would have at a youngish age.
One of the photos are from when it was younger, and the rest are current.
Rearranging their cage frequently, and limiting the light they get to 8 hours a day will help tremendously. Please be sure you never put a nest box or anything that could be used as a nesting site in their cage.
When they come into condition, limit the amount of protein in their diet at that time.