Your brother's wife is your sister in law, and it is perfectly natural to address her by her given name.
A hoe.
aunt
We call "Mami" to moms brother's wife.
probably by her name
sister in law
Brother-in-law
Pick up the phone
Shwe would be your sister-in-law.
errrr, no maybe nephew
Sister In law
Your sister-in-law.
You would refer to your younger brother's wife as "bhabhi" in Hindi.