Your first cousin.
The relation of the mother;s sister to daughter is niece-aunts.
your niece
First cousins, twice removed. Aunts daughter is your cousin. Aunts daughters daughter is cousin once removed Aunts daughters daughters daughter is cousin twice removed.
the daughter's cousin
yes
great nephew
Her aunts/uncles daughter.
They'd be your cousin.
A nephew is a cousin to his aunt's son.
Your Aunt's first cousin may be your second cousin, onve removed or may be no relation to you at all.
The grandchildren of any of your great uncles and great aunts are your second cousins.
your cousin