What is my sister's husband's sister to me?
Your sister's husband's sister is your sister's sister-in-law, and that is as close as English gets. She isn't your in-law: the marriage between your families is your sister's, not yours. Some people say co-sister-in-law, but strictly that word means your spouse's sibling's wife. Most just use her first name.
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Sister's sister-in-law
English has no word for this person. The marriage that links you is your relative's, not yours, so they aren't your in-law, and families just say “sister's sister-in-law”.
- You
- Your sister
- Her husband
- His sister
From the other side, you are their sibling-in-law's sibling.
This connection runs through a marriage, not a shared ancestor, so the ancestor chart can't draw it.
The calculator below works out blood relationships through a shared ancestor — use it to explore the rest of your tree.
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This relationship sits outside the shared-ancestor model, so the card above carries the answer and the calculator opens in its default state. Work out any blood relationship with it, or open the full relationship calculator.
Related questions
FAQs
Is my sister's husband's sister my co-sister-in-law?+
Not strictly. Co-sister-in-law means your spouse's sibling's wife. Some families stretch it to cover her, and nobody will be confused.
Who am I to my sister's husband's sister?+
Her sibling-in-law's sibling: the same unnamed link from the other side.
Does the calculator store my family details?+
No — it runs entirely in your browser. Nothing you enter is uploaded or saved on our servers.
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