Your first cousin's daughter is your first cousin once removed.
Your second cousin's daughter is your second cousin once removed.
It gets more complicated if you are talking about the daughter of a cousin who is one or more times removed.
Your niece and your daughter are first cousins. Your daughter and the daughter of your niece are first Cousins, once removed.
They are second cousins
The children of siblings are first cousins, so your daughter and your brother's daughter are first cousins to each other.
They are first cousins.
Your daughter and your niece's daughter are first cousins, once removed.
Phoebe and Hepzibah were cousins. Hepzibah was the daughter of Phoebe's uncle.
Your son and your niece are first cousins. Her daughter and your son are first cousins, once removed.
Your niece and your daughter are first cousins to each other.
You are second cousins once removed.
Your daughter would b related to her uncles child because they would b cousins
Your daughter's daughter is your grand daughter. Your nephew's daughter is the granddaughter of your sibling (your brother or sister) The grandchildren of siblings are second cousins.
Your sister's daughter and your son are first cousins to each other. Your sister's daughter and your son's daughter are first cousins, once removed to each other. Your son's daughter and your sister's granddaughter are second cousins to each other.