Mary's husband's father-in-law is Mary's husband's brother's mother-in-law, and Mary's sister-in-law is Mary's brother's stepmother.
How did this happen?
At your wedding, you are introduced to your new partner’s mother’s only sister’s husband’s sister in law.
What do you call this woman?
Mr. A meets Mr. B. B is the father of a son C and a daughter D. E is the mother of A.C is married and has one son. E is the daughter-in-law of B.
How is A related to B?
Pointing to a photograph, a woman says, "This man's son's sister is my mother-in-law." How is the woman's husband related to the man in the photograph?