Is the money a friend receives considered unlawful, given that her work in the hotel kitchen leads to her mixing with men and neglecting her duties towards her home and children, even though she does not consider that unlawful?

A woman's work is permissible if she adheres to the Sharia controls, such as avoiding unlawful mixing (ikhtilat), seclusion (khalwa), or neglecting her home and husband. Otherwise, she would be sinful, and repentance would be obligatory upon her, along with abandoning work that involves corrupting elements.

If her work is permissible, such as tailoring or cooking, then the money earned is permissible, even if it involved some corrupting elements. However, if the work itself is forbidden, like working in usurious banks, then the salary is forbidden, and it must be disposed of by spending it on charitable causes.

It is forbidden for a cook to work if it involves preparing prohibited items like pork and alcohol, and the money earned from it would be forbidden.

It is advisable to continue advising your friend.