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In order for this to be classified as a gift, no consideration would be given - it's money given to your wife with no strings attached. In no way should it be required that you give the funds to your wife's brothers and sisters that should be something that you just want to do.
If you just want to gift money to your wife's brothers and sisters, that's okay. Doing so will not invalidate the gift that your mother in law gave, or the transmutation agreement.
In terms of what the IRS considers.
Your mother in law will have to fill out a gift tax return for her gift to your wife, but no gift tax will be due.
You will have to fill out a gift tax return for the funds given to your brothers and sisters in law but no tax will be due.
If the gifts to my brothers- and sisters-in-law are all $14,000, would I still have to file a gift tax return?
No, not unless you gifted more than that
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