It's not possible to visually sex completely white cockatiels, be them wf lutino (albino) or wf clear pied, because they all look the same: white! However there are plenty of other ways to figure out sex. You can do DNA sexing, tell from personality or even possibly figure it out via the birds parents mutations.
Actually, it is possible to sex whiteface lutinos with the aid of an ultraviolet black light, the wing spots and tail bars are will be there if the bird is a hen. The eyes look red, but its hard to tell for sure on my phone. 66% chance this is a hen, we need pics ofthis bird under an ultraviolet light to confirm.
My female white face lutino has tail barring that is visible to the naked eye if you look in relatively good light. But, being that the bird in question is 3 months old and probably doesn't have adult plumage yet, the presence of tail barring is not reliable.