her 7th cousin.
Your aunt's daughter is your first cousin.
It would be a second cousin.
She would be your 2nd cousin.
The relation of the mother;s sister to daughter is niece-aunts.
your uncles daughter would be your cousin
3rd cousin I think:-)
Your daughter and your first cousin are first cousins, once removed.
Your first cousin.
3rd cousin I think:-)
Your wife's first cousin's daughter is your wife's first cousin, once removed, but is not related to you.
2nd cousin once removed
Your daughter and your third cousin are third cousins once removed to each other.