If anyone is having problems with the way TurboTax 2020 is calculating the Kiddie Tax, you might want to read all three pages of this post: https://ttlc.intuit.com/community/taxes/discussion/how-is-daughter-s-tax-rate-31-she-received-unempl...
There appears to be a bug in Form 8615 calculations. One person has posted a workaround that might apply in some cases. While trying to implement the workaround, I discovered my numbers were off due to confusion between each child's Schedule D (or lack thereof) and the Form 8615 Schedule D worksheet. So I can't say for sure if the June 2021 updates have fixed the problem of high tax numbers (presumably because Form 8615 might be using estate tax rates instead of the parents' marginal rate). If they haven't, you can try the workaround listed above.
