"how should she answer the “was the entire amount for an RMD or not” TT question prompt?"
It doesn't matter. This particular question is asked only to determine how much is eligible for rollover. In this case, the distributions was not rolled over. (A distribution paid to a non-spouse beneficiary is not eligible for rollover.)
"Will answering “yes” as opposed to “no” cause TT calculate the taxes due differently—or incorrectly?"
In this case, no. In the case where someone mistakenly rolled over an RMD, TurboTax will behave differently by allowing to be reported as rolled over only the amount in excess of the RMD. Answering that the entire amount was RMD prevents TurboTax from even asking about rollovers or Roth conversions.
