there is a substantial difference between w-2 wages and earning the same amount as self-employed. with a w-2 social security and medicare are deducted from the paychecks. with self-employment net income there is no withholding for these taxes so you and she will owe these as additional taxes. her social security wages are subtracted from the social security wage SE income base of $147,000 to determmine the maximum SE income subject to social security taxes of 12.4% approx ) but there is no limit on Medicare taxes. which would be about 2.9% may want to review schedule SE
https://www.irs.gov/pub/irs-pdf/f1040sse.pdf substitute $147,000 for the amount on line 7
There will be no federal penalties for not paying in enough taxes during the year if withholding
1) And timely estimated tax payments equal or exceed 90% of your 2022 tax
or
2) And timely estimated tax payments equal or exceed 100% of your 2021 tax (110% if your 2021 adjusted gross income was more than $150K)
or
3) the balance due after subtracting taxes withheld from 90% of your 2022 tax is less than $1,000
or
4) your total taxes are less than $1,000
state laws differ
with uncertainties, I would recommend you adjust your federal withholding (including your spouse's) to be 100% of your 2021 tax (110% if your 2021 AGI was over $150K)
meeting a safe harbor criteria avoids penalties but you may owe a lot for 2022 come 4/15/2023. some taxpayers don't like this and will pay in more than required. this is up to you.
