Here are a few things to check.
A maximum of $112,000 (for 2022) of foreign earned income can be excluded. If your wife made more than that, her remaining foreign income cannot be excluded and is taxable.
Make sure you did not make a mistake entering the amount of your wife's foreign income. The excluded amount is on Schedule 1 line 8d, as a negative number. Also look at Form 2555 to see if you spot any errors.
You can see how the tax is calculated on the Foreign Earned Income Tax Worksheet. If you are using the CD/Download TurboTax software you can look at this worksheet in forms mode. If you are using TurboTax online you can see the worksheet if you save a PDF of your tax return and select the option to include government and TurboTax worksheets. Or you can see the worksheet on page 35 of the IRS instructions for Form 1040 and work through it yourself.
