Questioning TurboTax Tax-owed calculation

I hate to even bring this up, but in doing my sister's (70+) 2021 taxes, she comes up with a Line 15 Taxable Income of $49,044 - and the TurboTax calculated Tax on Line 16 shows a Tax of $6,357.

 

I am sure I am missing something, and I shouldn't complain since the tax is lower,

but when I do the tax calculation by hand, I come up with a tax of $6,538.

(2021 Tax brackets of $9,950, $40,525 for the 10%, 12% & 22% brackets - giving $8,519 @ 22%)

 

Additionally, using one of the on-line Tax calculators, they also come up with a $6,538. Tax.

 

Even using the Tax Table from the IRS 2021 Publication 17 Tax Guide, it shows a Tax of $6,534.

 

SO, WHAT ARE WE DOING WRONG?

 

ron in shawnee