What is the ruling of Islamic law on a married man taking a second wife, and what are the psychological consequences of divorce for children?

A woman does not have the right to demand a divorce merely because her husband married another, unless she stipulated this in the marriage contract.

If she is unable to remain with him, then she may seek a khul‘ (divorce at the wife’s instance, usually for a compensation). It is advisable to be patient and not destroy the family due to jealousy, as divorce has significant psychological and social harms for the woman and the children. Many women who divorced for this reason later regretted it. She should seek Allah’s help and increase her remembrance of Him and supplicate to Him.