Is it Islamically permissible for a fiancée to break off her engagement from her suitor if she does not find in him what he was described to possess regarding good treatment, and she does not feel an inclination or sense of security towards him?

It is permissible to break off an engagement due to aversion to the suitor, because this is a contract whose harm persists, and the fiancée has the right to take precautions for herself. Nevertheless, it should be known that the suitor is a stranger to the fiancée before the legal contract, and it is not permissible for them to speak to each other without need, let alone utter words of love. Therefore, one must repent to Allah Almighty for overstepping in speech with the suitor, and adhere to the boundaries of Allah. If the aversion persists, the advice is to leave the suitor after consulting the family and performing Istikhara.