Your cousin's wife is considered your cousin-in-law. This means that she is related to you through marriage, but not by blood.
The children of your wife's first cousin are her first cousins, once removed. They are not related to you.
If it is not your common grandparent, there is no relationship.
dappy and tulisa are cousins
You are cousins
Cousins
They are cousins.
You are First Cousins
You would be 2nd cousins, assuming that the brother's wife's granddaughter is also the brother's granddaughter. If the granddaughter is not the granddaughter of the brother, there is no relationship.
You are second cousins
They are cousins.
First cousins
Second Cousins