If you get divorced from your husband, all of his relatives stop being referred to as your in-laws.
sister in law
Your Sister-in-law
Your brother would call your husbands sister by her first name. Or, "my (sibling's) sister in law.
Your sister's husband is your brother-in-law.
brother in law
Mom
No. Your husband's sister-in-law is either your sister or the wife of one of his siblings. If she is the wife of one of his siblings, she is not related to you.
Sister-in-Law
He is brother your brother in law.
I think that you call them your cousin in law because its pretty much the same concept as a sister in law... its your husbands cousin so it would be a cousin in law
There is no common ancestor, so you aren't really related. Related by marriage is one way to describe the relationship.
Yes, I suppose that they would be sister-in-laws. Because your sister is your husband's sister-in-law, and the other sister is his sibling, then I suppose they would be sister-in-laws.