Oh, sure. It's easy!
I balanced the playbooks across stats, moves & crap all together, not across each individually. The battlebabe has better stats because she has worse moves. The hardholder has terrible moves because she has excellent crap. The driver has worse stats because her combination of moves and crap would put her ahead if she didn't.
In the battlebabe's case in particular, it's not that her moves are worse individually, it's that they're basically all keyed to her non-high stats. The gunlugger gets to do all her moves with hard, for instance, where the battlebabe does her moves with hot, weird, sharp, and a Hx/cool split. The battlebabe gets that extra +1 to her stats to make up for it.
If your irritated player has a Shadowrun background: it's a priority system, that's all. The battlebabe's the only playbook built with 1st-priority stats, and the driver's the only playbook built with 3rd-priority stats.
If she's concerned that some stat lines in the other playbooks add up to +2 while most add up to +3, I can answer that too: the ones that add up to +2 are the ones with a second +2 stat in them. A second +2 stat "costs" +3 instead of just +2.