Technically, the sister of your daughter-in-law is not related to you at all, although she is your son's sister-in-law. Most people would introduce her as the sister of your daughter-in-law.
daughter-in-law
One of the twin sons of Judah by Tamar (Genesis 46:12)(Numbers 26:20)(Ruth 4:12)
It is only with the utmost respect that I direct your attention to the spot on your blouse.
My daughter in law withheld a toy from my granddaughter who then threw a tantrum and threw a dumbbell at my roommate's hitchhiker, who then became cutthroat and using a fishhook kicked the knickknacks out of everyone in the car.
Your sister's sister is your sister.
Yes, the sister of your spouse (wife or husband) is your sister-in-law. In addition, the wife of your brother is also your sister-in-law.
Sister My Sister was created in 1995.
If your sister in law is your wife's sister then she would be nothing to your sister. However if your sister in law is your brother's wife then she would also be your sister's sister in law.
There are two ways you can have a sister-in-law. In one case, her sister is also your sister-in-law and in the other she is not. Your sister-in-law can be the sister of your spouse. Then your sister-in-law's sister is either your wife or is also your sister-in-law. Your sister-in-law can also be the wife of your brother. In that case, your sister-in-law's sister is not related to you.
Real sister, half sister, or step sister
The duration of Sister My Sister is 1.48 hours.
Sister