If my 2020 tax return is still processing, would I get a second check for the correct 3rd stimulus package ? They will go off my 2019 that does not include my kids.

[JamesG1]

If your 2020 Federal 1040 tax return has not been processed, the IRS will issue a third stimulus check based upon 2019 tax information.

This TurboTax Help states:

Do I need to do anything to get my stimulus check?

You don’t need to do anything to get your stimulus check. The IRS will determine eligibility based on your last tax return (either 2019 or 2020) and will likely send your payment to the bank account where your tax refund was deposited.

At this time, we do not know how or when the IRS will process a second payment for your new dependent.

Follow the TurboTax COVID Tax Center and the IRS Economic Impact Payment Information Center as further updates are issued by the IRS.

[Jennifer827]

So I will not be able to report the correct amount I should of received until next tax season? That's 2,800 I will not get this year. 

[ErnieS0]

The IRS has not said how it will deal with missing third stimulus payments yet.