@LocHa - if her W-2 income is under $13,850, there is no filing requirement!
HOWEVER, is there were any federal tax withholdings, the only way to get them returned is to file a return....and if she doesn't file to get the money back, the IRS is pleased to keep it 😀
please read:
https://turbotax.intuit.com/tax-tips/irs-tax-return/does-everyone-need-to-file-an-income-tax-return/...
