Why is my wife’s withholding so low ?

[jerrym98]

We both made roughly the same amount ~22,000 but my wife actually owes money this year. After looking at our w2s it looks like her withholding is significantly lower than mine (about a third of what was withheld from me). Why is this ? We both only have our w2s no extra forms and we both made around the same both are residents of the same state so why was her withholding so low throughout the year that now she owes money ?

[Bsch4477]

She should look at the W-4 she submitted to her employer. That form determines how much is withheld. 

[jerrym98]

What would we look for on her w4? The only thing off about her current w4 is that for step 2 it hasn’t been properly filled out to reflect that we both work and adding my income to that section.  Would we have to look at an older w4, are they issued yearly like w2s? The current w4 of hers is the December 2020 revised version