Male and female lutinos look exactly the same can't be visually sexed unfortunately. Does the luntino ever sing or bob his head? If so... it's a boy ... if the luntno NEVER sings then the luntino most likely is female. My male tiel started singing a lot when he was only 4 months old... if the lutino is a male you will know by how vocal he is.... by vocal I mean actual singing/whistling, not screaming/flock calling.
How old is the pearl? If he/she has gone through the first molt then the pearl is a female because male pearls lose the pearl coloring after the first molt.