I personally think Yumi has a lilac cere. Iβve had some people say definitively a girl whilst others say definitively a boy so i guess we will have to wait and see in a few months π
She was bred by a breeder who breeds budgies for show purposes. I wouldnβt know the difference between crest sizes etc.
She appears to be a girl, since her cere is light blue and white. She is young, but if she were a male, her cere would be pink and slightly iridescent.