The 1099-R is issued for the tax year of the distribution. It's not annual reporting; it's for the payout event.

"I forsee a big problem with IRS because there was no 1099-R"

That has nothing to do with the tax treatment, which was optionally to include it all in income in that one year. Or, the default is to include 1/3 of the amount as taxable income in 2020, 2021 and 2022 as is typical to disaster distributions.

"(her 1/3 of the 2020 Form 1099-R Gross Distribution for 2021)"

If there is no new distribution, there will be no new 1099-R, and you don't need another 1099-R for a distribution that happened in a prior year. You are not deferring or spreading the tax. It is simply additional taxable income that contributes to the total on the 1040, each year of reporting. If there is a new distribution for 2021, it has nothing to do with covid provisions. That is handled separately.

If you prepared the 2020 taxes, there should be an 8915-E with the carryover. That's what the IRS uses to determine who should be including 8915-F in 2021 and, if applicable, in 2022. If 8915-E was not included in the 2020 tax year filing, that should be amended.