Whether or not the distribution is an RMD is not a factor in determining whether or not a distribution qualifies as a QCD. The requirements to be a QCD are:
- the distribution is from the pre-tax money in the IRA,
- the one for whom the IRA is maintained is age 70½ or over,
- the distribution is sent directly to the charity from the IRA,
- the charitable contribution would otherwise qualify to be reported on Schedule A,
- the QCD limit of $100,000 per year is not exceeded, and
- with the changes in the tax code in the SECURE Act, the individual must subtract out the amount of deductible traditional IRA contributions made after age 70½ to their own IRA. (This particular requirement get's a bit weird when the QCD is being made from an inherited IRA, but does not apply in this case.)
§ 408(d)(8)(B)(ii)
which is made on or after the date that the individual for whose benefit the plan is maintained has attained age 70½
https://www.law.cornell.edu/uscode/text/26/408
