Is the fiancée obligated to return gifts and money to the fiancé after the engagement is broken, given that some of them have been used and the money has been benefited from by both parties?

If a man proposes to a woman and gives her gifts, and then she refuses to marry him, he has the right to reclaim the gifts. This is the view held by Sheikh Al-Islam Ibn Taymiyyah, Al-Mardawi, and Al-Zarkashi. The woman must return the gifts that are still existing, and for those that are damaged, she should return their equivalent or their value, as mentioned by Al-Jamal and Al-San'ani. However, anything that the suitor himself damaged or consumed, he has no right to claim back from her. It is important to note that the suitor is a stranger (non-mahram) to the fiancée, so private seclusion (khalwa), shaking hands, and going out with her are not permissible.