Indeed, when she first decided to do triathlon, she commented that "riding a road bike was very different" so presumably had been doing off-road riding up to that point.
Her ironman time is a little outside that of my stepson (same age group) and I know how hard he had to work to fit training in around a full time job. Cycling is his worst discipline too, and the one where he improved the most between the two events he has done at that distance.