Answered by Sayyidi al-Ḥabīb `Umar bin Hafīẓ (may Allāh preserve him and benefit us by him).
How do we protect our children from being affected by an environment which is not conducive to their Islam?
We do this by reminding them of the religion and establishing gatherings of remembrance and knowledge for them. We need to warn them repeatedly about things which they may see which are in contravention to the Sacred Law. They should not go out too freely in this environment but rather other activities should be arranged for them which protect their religion. We should also pray for them in abundance and teach them to love the Messenger, the people of the Prophetic House, the Companions and the pious.