Your nephew's daughter is your great niece. Her son is your great great nephew. You are his great great aunt (if you are a woman) or his great great uncle (if you are a man).
The sons of your son-in-law's siblings are his nephews. You are not related to them.However, your son-in-law is married to your daughter. The sons of her siblings are also your son-in-law's nephews. They are your grandsons.
Second cousins once removed.
Your daughter's son is your grandson and you are his grandma or grandpa.
It does not appear that Thomas Jefferson had any nieces or nephews. He had a daughter, a son in law and two grandsons. He also had an aunt and a first cousin.
your 5th cousin
The person is your nephew :)
They are second cousins
Your son and your niece are first cousins. Her daughter and your son are first cousins, once removed.
Amanda Perez has no children she has many nieces and nephews.
Your cousin's wife is not related to you or to your daughter - unless your daughter marries their son or your wife is related to your cousin's wife.
Your son-in-law's brother's son is not related to you, but is your daughter's nephew.
You are not related to your daughter-in-law's sister, although she is your son's sister-in-law.