If it is a woman, then the relationship with the cousin should be brother and sister. Then their children should be called cousins and cousins should be called uncles and aunts. If it is a man, then the relationship with the cousin is a brotherly relationship, and the children should be called cousins, cousins, uncles and aunts.

Your child's name for cousin is actually the same as cousin and sister-in-law. After all, it is a family with a surname, and it is also an elder for children. Every place has a different name.