She is, for all intents and purposes, an adult. The others are children. Not only is she the one that should be setting a standard of respect and forgiveness in order to guide them all to a better path, she's actually even exploiting the girls that believe her to be their friend. She treats the girls like toys to entertain her, taking advantage of their trust. If they knew who she really was inside, not to mention the kinds of thoughts she's had about them, they would be rightfully shocked.
Or at least they would be if Ren ever faced negative consequences for her actions. But she succeeds in everything she does and is beloved by everyone despite at heart a selfish old perv.