Oh, what a lovely question! You can call your nephew's daughter your great-niece. It's a beautiful title that reflects the special bond you share with her. Just like a happy little tree in a painting, your relationship will continue to grow and flourish with each passing day.
A cousin, in all those difficult cases they are your cousins
Your daughter and your nephew are first cousins. His daughter is your daughter's first cousin, once removed.
your nephews
Nephews
Some would call your nephew's children your grand nephews and grand nieces, others would call then your great nephews and great nieces.
your niece's or nephews
If it is a boy then it is your nephew. If it is a girl then it is your niece.
Your husband's sister's kids are referred to as your nieces and nephews by marriage. More specifically, you can call them your "nieces" if they are girls and "nephews" if they are boys.
nephews!
Children of your siblings are nieces and nephews. Children of your spouse's siblings are still called nieces and nephews, but you are not related to them by blood.
Your daughter is you great nephews great cousin if u live in Australia ,USA ,UK
Second cousins once removed.