This is the parents.You have one pearl chick (the grey one). Definitely a girl, since a pearl mother is required to get pearl boys and you haven't said that the mother is pearl. If the yellow one has red eyes it's a lutino, dark eyes would indicate a clear pied. If this chick is lutino, she is also a girl since a lutino mother is required to get lutino boys. If this chick is clear pied it could be either sex.