Aunt and nephew
If your daughter-in-law's grandson is a child from a marriage before she married your son, or after their marriage ended, her grandson is not related to you. If he is a child of the marriage between your son and your daughter-in-law, then he is your great grandson.
The relationship between your brother's daughter and your granddaughter is that they are first cousins. This is because your brother's daughter is the child of your sibling, making her a cousin to your child.
You are their aunt or aunt by marriage.
Your grandson and your brother's grandson are second cousins to each other.
nothing
a relationship between brothers should be sacred and good....
First cousins
First cousins
Cousins
Your daughter and your aunt's children are first cousins to each other. Your daughter and your aunt's grandson are first cousins, once removed, to each other.
grandfather grandson.
Your daughter's daughter is your granddaughter, and you would be her grandmother or grandfather.