Silly q regarding bad tax math
Hey all, essentially the situation is my sister was working a job and decided to give all of her income to my mom as a gift, but just wants my mom to cover her tax liability. She is married filing jointly in the 22% tax bracket and made 36899 (so this would be box 1 on the W2). She had 2169 withheld.
In 2025 mom has been giving her 600 a month so 7200 a year. When I did the math, I figured that she owed 36899 * 0.22 = 8118 in tax from that job, and my mom gave her 7200 in cash so the only tax liability left over is $917. My sister had 2169 withheld from her checks so my mom shouldn't owe her anything now for taxes.
My sister figures differently she figures that her pretax income was 36899 so my mom should do (36899 - 7200) and then pay taxes on that. It doesn't make sense to me. It feels wrong but why is it wrong?