The sentence makes no sense. I have never heard the word compensational and don’t think it is a word. Are you there is no typo in the sentence?

sometimes speakers will add on suffixes to words to make a new word. They do this to try and make a point or express an idea. demure=for a woman shy, reserved compensate= to react in an opposite manner. if you are about to hit a bridge on your right when driving you compensate by steering harder than usual to you left. suffixes are normally put on a word to make it an adjective. comfort , comfortable. etc my guess is someone is trying to say a demure woman tries to hide her shyness by acting in an uninhibited fashion. This would be the only context I can think of where demure compensational (made up word) would work.