Sister or by her first name
Your brother's wife is your sister in law, and it is perfectly natural to address her by her given name.
Your younger brother's wife is your sister-in-law. Your older brother's wife is also your sister-in-law. In English, we make no distinction between the two. However, when talking to your sister-in-law you do not address her as sister-in-law. You just call her by her name.
Your spouse's sister is your sister-in-law and your spouse's brother is your brother-in-law. The English language has no term for a relationship between you and the wife of your brother-in-law or the husband of your sister-in-law. The best you can do in English is to use "my sister-in-law's husband" and similar phrases.
You are your brother's wife's brother-in-law, if you are male. But your brother's wife can also have brothers-in-law who are not related to you or to your brother. They would be the husband's of the wife's sisters.
Your wife's brother is your brother-in-law.
Your wife's brother is your brother-in-law. Your brother-in-law's wife is not related to you, and the same applies to her sister.
The husband's brother is a brother-in-law to the wife. The wife's brother is a brother-in-law to the husband. However, the husband's brother is not related to the wife's brother.
Your wife's brother is your brother-in-law.
No, legally she is your brother in-law's wife.
younger brother's wife -- maradalu elder brother's wife ---vadina
I think you should address her by her name. She is no relationship to you, but you would introduce her as your nephew's wife.
Your wife's brother would be called "brother-in-law".