Seems a bit unfair, convicted without evidence then punished. An inspection with fingers would have confirmed any evidence of the clitoris being rubbed or stimulated.
As a schoolgirl, her sexuality should be of very little interest, as well as that she writes good grades, does her homework diligently and learns how to serve her future husband.
Yes no reason needed at all to spank, cane or slipper her ass hard, if she happens to have been naughty just means she could get it even harder would you not say.