Does the fiancée's religiosity that stems from obedience to her fiancé count as true religiosity that would motivate the fiancé to keep her, or must her religiosity stem from the fear of Allah Almighty for her to be a righteous wife?

A righteous woman is one who fulfills her religious obligations out of fear of God's punishment and hope for His reward. She is the best treasure a man can possess. The Prophet, peace and blessings be upon him, said: "So win the one who is religious, you will be successful." And he also said: "The best treasure is a righteous woman: when you look at her, she pleases you; when you are absent from her, she guards herself; and when you command her, she obeys you." If the fiancée performs acts of obedience based on her fiancé's command, her persistence may lead her to perform them seeking God's pleasure. The fiancé should guide her towards God by sending her beneficial materials that encourage her to perform acts of obedience for the sake of God.