When will Turbo Tax reflect the new child tax credit signed into law by President Biden on 3/11/2021?

The Child Tax Credit increase is effective in tax year 2021, not in tax year 2020.

The new (expanded) Child tax credit ($3000; $3600 for kids under 6) is effective for 2021. There is a provision for advanced monthly payments  being made in 2021. The payments will come from the IRS, similar to the stimulus payments. The details of how and when are yet to be worked out, but  starting in July has been mentioned.

Getting the expanded child tax credit has nothing to do with filing your 2020 tax return. Whether you already filed, file now or file later, the additional money will not be part of your 2020 tax refund.

References:  https://www.kiplinger.com/taxes/602378/senate-passes-3000-child-tax-credit-for-2021

https://www.nytimes.com/live/2021/03/06/business/stimulus-check-plan-details#when-will-stimulus-checks-arrive https://ttlc.intuit.com/community/tax-topics/help/how-will-the-stimulus-package-impact-me/00/1393859