You'll get a lot of debates of whether a screwball is a legitimate pitch or not, put that aside. Bottom line is that if both have the same spin she's not throwing one (or both) of them correctly.
If a pitcher can spin the ball > 25rps at close to 9-3 axis how can it not be a legitimate pitch? As with the riseball where people get off the rails with respect to the screwball is that it is a difficult pitch to master and very few ever throw it properly. Most claims of those throwing the pitch correctly are dubious at best.
My DD throws it and it's incredibly effective. No disagreement here.
If a pitcher can spin the ball > 25rps at close to 9-3 axis how can it not be a legitimate pitch? .
We get into these discussions regularly.
Perfect Circle's DD does get 3-9 spin...but she isn't throwing the ball particularly fast. Will she be able to throw the ball at 60MPH with anything close 3-9 spin? I doubt it.
I have yet to see a 3-9 pitch at varsity level of HS softball, college or pro.
At the upper levels, the screwball is a "step left, throw right" pitch with bullet spin.