I'm a little perplexed. You know the particulars of her current challenge, but if she can manipulate a revolver and speed loader or speed strip, why wouldn't she be able to manage an auto pistol and mags? Or is racking the slide the big challenge? Generally, when engaging in CCW, one has time to chamber the first round at home where there's time and/or help. Once that's accomplished, you're good for 10, 12 or 15 before a reload and the slide can be released from open or the mag changed with one still chambered, eliminating the need to manually rack it again. Or push the front of the slide against the edge of a piece of furniture, edge of the counter-top, the door jamb, bed frame, anything hard enough while gripping the pistol in the weak hand and let it slip off to chamber the next round. If an auto is what she's already familiar with, wouldn't reducing the need for cross-training while preserving her tactical advantage be better? Limiting one's self to 5 or 6 guarantees having to reload much sooner. If the confrontation takes 5-6 rounds do you want the gun to be empty or still have 4 or 5 or 10 left - without needing to find refuge for a reload? After a shooting scrape, no one says, "Gee, I sure wish I didn't bring all that extra ammo!"
I give no credence to the idea one can predict what a future defensive situation will require based on statistical history. Statistics provide a general predictive value, not specific. Yes, statistically many shootings are over in just a few seconds and after a few rounds. This is no predictor of the next specific confrontation and there are many which are atypical for various reasons. In some number of instances, one will face multiple assailants, some drugged out of their minds and capable of absorbing multiple hits before incapacitation. Just sayin'.