@Anonymous I see where you are going with this.
If the qualifying person is your child or grandchild then you are eligible for Head of Household even if they do not meet the Citizen or Resident Test.
IRS Publication 501 Table 4 page 10 - https://www.irs.gov/pub/irs-pdf/p501.pdf#page=10
Then your workaround for the person being a non-dependent and enter NRA in the box for the Social Security number will work.
TurboTax does not allow a tax return to be e-filed if the SS field is not entered with a number. The IRS will not accept an e-filed tax return without a number in the SS field.
The tax return can only be printed and mailed.
