Are the sons and daughters of the husband of the mother of the maternal cousin whose son the wife suckled considered unmarriageable (mahram) to the wife and her children?

If your wife suckles from her maternal uncle's wife, then her maternal uncle's son becomes her brother through suckling, and her maternal uncle becomes her father through suckling. All of his children, both from the wet nurse and others, become her siblings and mahrams to her and her children. There is no difference in this whether the wet nurse remains a wife, is divorced, or passes away. The effective suckling consists of five sucklings within the first two years of life, and a suckling is considered when the child sucks from the breast and then releases it for any reason.