Her ability to crush rocks in her hands is a rather bewilderingly strong power-up, given that her stats [as previously displayed two chapter sections ago] seem to have only increased by roughly +50% across the board (aside from MP, which remained static).
Even if we account for baseline strength elements [eg, the basic strength value we need just to lift our muscle and bones, etc; the consideration for which would increase the effective % gain from a stat boost, assuming mass and the like doesn't also increase in comparative measure] and consider her to have had world-class strength to begin with (due to being an exorcist), the increase from about 280 attack to about 400 attack doesn't seem like it'd be enough to explain rock-breaking [assuming it's a rock of typical density, rather than a soft, chalky one]. So I suppose the three most likely explanations are that exorcists are already well beyond world-class to begin with, that the author just isn't good with numbers, or that the stat system doesn't use a linear progression rate.
Anyone have any thoughts?