You are not related to your cousin's wife.
Your cousin's wife is not related to you, so her cousins is not related to you unless she has some family connection to you besides being the wife of your cousin.
Your brother's wife's cousins are not related to you and the English language has no special term for that. The same applies to the cousins of a stepbrother's wife.
You are second cousins
It depends! For example, are you the uncle's child? That would make you and your wife first cousins. But you are not related to your wife's uncle if your only link to him is by marriage to her.
Your cousin's wife is not related to you, so her cousins is not related to you unless she has some family connection to you besides being the wife of your cousin.
They are out of synch by a generation. They would be first cousins once removed.
If your daughter is also your wife's daughter, your daughter and your wife's first cousin are first cousins, once removed, otherwise they are not related.
Theodore and Franklin Roosevelt were distant (fifth) cousins. Franklin's wife, Eleanor Roosevelt , was Theodore's niece .
She would be your aunt. The neice's kids will be your second cousins.
The children of your wife's first cousin are her first cousins, once removed. They are not related to you.
Your father's brother's wife is your aunt, but her cousins and their children are not related to you.
If you are close to your step-brother, or to his wife, you can call her your sister-in-law. If you are not close, you can call her your "step-brother's wife."