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."
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.
The wife of a stepson is usually called a daughter-in-law.
Derek Huff (Adam Scott)'s wife Alice is portrayed by American actress Kathryn Hahn in the 2008 film Step Brothers.
In Marathi, brother's wife is called 'vayni'
Your brother's wife is your sister-in-law.
they would be called step sisters or step brothers
Your Mother or Step-Mother.
Your brother's wife's kids would be your nieces or nephews.
step father in law
No, he only has a sister called Tootie.
step brothers
I think your step grandma.
The second wife to your father if she is not your mother is called your step mother .
That would be your great-aunt, by marriage.