One child of female i-3 has albinism. what is the probability that any of the other four children are carriers of the allele for albinism?

Albinism is a recessive trait so both parents must have the recessive allele for it to occur. Let A be the dominant allele and a be the albinism allele.

Parents: Aa x Aa (considering neither were albino)

Children possible genotypes: AA, Aa, Aa, aa

Possibility of a child being a carrier: 50%