I'm not sure why you say that Stipends are not subject to kiddie tax? I do agree that they are taxed as income not subject to self-employment tax. Although I can't find anywhere the IRS actually refers to a "stipend," it is my understanding they fall in the general category of taxable scholarships and grants. The instructions for form 8615 say:
"For Form 8615, “unearned income” includes all taxable income other than earned income. Unearned income includes taxable interest, ordinary dividends, capital gains (including capital gain distributions), rents, royalties, etc. It also includes taxable social security benefits, pension and annuity income, taxable scholarship and fellowship grants not reported on Form W-2, unemployment compensation, alimony, and income (other than earned income) received as the beneficiary of a trust."
Likewise, the stipend will be reported to the child on 2022 1099-Misc Box 3. It appears to me that TurboTax treats this box as unearned income unless specifically told not to.
