If the W gene is epistatic to the B/b gene, the presence of a dominant W allele would mask the pigmentation brought by the B/b gene, leading to white cats. For a cross of WwBb, the Punnet square result would show the following:
Your neighbor, a "crazy cat lady", has two white cats with the genotype WwBb. You learned in genetics that the W allele shows dominant epistasis over the B gene, and the B allele (black) is dominant over the b allele (brown). If your neighbor crosses her two white cats, what phenotypic ratio would you expect in the litter?
Make sure to include the phenotypes in the ratio.