Can you give us an advice about customary or secret (not documented) marriage in the following situation: my sister is divorced and has two kids and she is afraid of marriage officially and her husband will take her kids. On the other hand, the man who want to marry her afraid that his wife will leave country with his son as she is Arab not Egyptian. Is it possible and Halal to get marry Orfy (secret) because if it is not Halal they will separate and forget the issue. Just their situation made them to think about Orfy (secret marriage).

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

In regard to secret marriage, please refer to Fataawa 81385, 39267, 82536, 120282, 195979, and 89293.

Know, also that the divorced woman loses the right of guardianship of her children as soon as she gets remarried. So, it is unlawful for your sister after she gets married to keep that secret in order to guard the children. In fact, the guardianship in this case, is transferred to her mother.

Allah knows best.