What is the ruling on a Sunni woman marrying an Ismaili man, if her family might not approve of her marrying him?

The Isma'ilis are a batini (esoteric) sect whose outward appearance is Shi'ism, claiming allegiance to the Family of the Prophet, but whose true nature is to dismantle the doctrines of Islam. Marriage to someone in this state is impermissible. Loving such a person is a tribulation, and associating with him is harmful. It is not permissible for a Muslim woman to be in a romantic relationship with any man who is a stranger to her. Sincere repentance is required, and the relationship with this young man must be severed. Satan gradually leads people to temptation, step by step, as Allah Almighty says: "O you who have believed, do not follow the footsteps of Satan. And whoever follows the footsteps of Satan - indeed, he enjoins immorality and wrongdoing." [An-Nur: 21]. One must hasten to repentance, for Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" [Az-Zumar: 53]. Gender mixing in studies is a cause of many corruptions and evils. It is not permissible for a Muslim woman to continue in such an environment except out of necessity or severe need, and on condition that temptation is safeguarded against.