What is my wife's brother's wife to me?
Your wife's brother's wife is your co-sister-in-law. English never coined an everyday word for the spouse of your spouse's sibling — two marriages sit in the chain, with a pair of siblings between them — so the genealogical 'co-' label and first names do the work. No blood connects you at any point.
Relationship
Co-sister-in-law
English has no single formal word for this relative — “co-sister-in-law” is the label genealogists use.
- You
- Your wife
- Her brother
- His wife
From the other side, you are their co-sibling-in-law.
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.
Loading tool…
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.
FAQs
Is my wife's brother's wife my sister-in-law?+
Strictly no — 'in-law' covers one marriage step. With two marriages in the chain, genealogists say co-sister-in-law.
Who am I to my wife's brother's wife?+
You are their co-sibling-in-law too — the relationship reads the same from both ends.
Does the calculator store my family details?+
No — it runs entirely in your browser. Nothing you enter is uploaded or saved on our servers.
Start with one relative and see what comes back.
Add what you remember and AncestorIQ searches for the rest. Free to build your tree for as long as you like.
No credit card needed. Your tree stays yours.
