The answer to TurboTax's question asking if the IRA was inherited only affects what questions TurboTax asks. Nothing about the answer itself appears on your tax return. The only case where indicating that it's not inherited could affect how the distribution is reported on your tax return is if less than the entire amount was rolled over and you have basis in nondeductible traditional IRA contributions in your own IRAs, in which case the taxable amount would be calculated incorrectly.
You'll still use code 4, the code present on the Form 1099-R.
