What metaphors are used in If There Be Thorns by V.C. Andrews?

There are both literal and metaphorical desires. While sexual desire was at the heart of this story, there are other desires at work. It seems possible that the revelation of Cathy's relationship with Chris would have been avoided or at least postponed if Madame M. hadn't shown up, and it should be noted that Madame M. likely would not have arrived if Cathy hadn't been seeking an opportunity to fulfill her own desire - a performance with Jory, son of Julian. Fulfilling this desire results in a serious injury to Cathy, one she'd been warned as a possibility.