You are confusing the various statements.

How can this even be true? "so the answer that I keep getting is she is not entitled to EIP 1 but she is entitled to EIP 2"

She did not Return to life in 2020 to be impacted by the covid disaster. There is no Splitting of 2020.

The people who had died in the meantime while the old tax returns were being used for Advanced payments, didn't get to keep the money, because they were not alive in 2020. Using a 2018 or even a 2019 tax return did not point out to the IRS they just sent the EIP to a dead person.

The arrival of the checks has nothing to do with any analysis. That's just the Banking.

The Code stated that a person alive in 2020 is impacted and gets the payment, and the payments happened in two parts already, and a likely third part. Just like the 2021 payment that already arrived is the Second payment of 2020 and is being reported on the 2020 tax forms.

You can read the CARES act yourself, you know.