Because it has been more than 5 years since the beginning of the year for which the decedent first made a Roth IRA contribution, any distribution from the inherited Roth IRA will be nontaxable.
Under the 10-year rule, no distributions are required from an inherited Roth IRA until the end of the 10th year following the year of death, so you could take a single distribution at the end of the 10th year and that distribution will be entirely free of tax.
