Was 2019 the year your wife reached age 70½? If so, the RMD is not late and nothing special needs to be done with your 2019 tax return; the distribution in 2020 will simply be reported on the 2020 tax return.
If 2019 was not the first year your wife was required to take an IRA RMD, waiver of the excess accumulation penalty is done by filing Form 5329 with the request for the waiver. TurboTax prepares this automatically if TurboTax asks if you completed the RMD for 2019, you answer No, and you indicate the amount on which you want to request the waiver, in this case the full amount of the RMD. TurboTax prompts for an explanation statement where you can provide reasonable cause. You can mention that T. Rowe Price admitted fault, but attaching the letter from T. Rowe Price is not necessary. Just keep the letter in your tax file in the extremely unlikely event that the IRS asks for additional information. The IRS seems to accept any explanation other than one that indicates that the RMD was taken late intentionally.
If you really want to include a copy of the letter, you'll need to mail your tax return.
