Sparviero grigio perla o no??

It is difficult to say just on a photo.
The best way to know it is breed with her.
She have possible 4 (modificated) genes in here.

-On the E-locus : E/E (if she is pure for this or E/? if she is unpure for this but it is a dominant gene producing the same phenotype whether its allele is identical or dissimilar)
-On the lav-locus : lav/lav (here she IS pure otherwise you NOT could see lavender = recessive genes producing its characteristic phenotype only when its alleles are identical)
-On the B-locus : B/- (here she is always pure because (cuckoo) B = Barred is a sex-linked gene and here a hen have only one allele of the other is a "-"
-On the S-locus : S/- (here she is also pure because (Silver/gold) S=Silver/s+=gold is a sex-linked gene here a hen have only one allele of the other is a "-"