Reality- virtually no pro riders can flat foot bikes in race trim, nor can many even double tip toe em.
But the lengths people go pursuing that is mind boggling.
If you skew the geometry of an R6 with a 4 inch drop in the rear, you'd be better off riding anything else. That things gonna wag the tail and/or run wide like crazy.
Recommendation- Boost her confidence with reassurance and have her one foot it, canted to her strong side. If she just cant get comfortable like that, swap it out for a smaller ride, realistically not a sport bike.