All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Generally, when a person socialises with people in order to obtain some benefits, he is encountered with some envy and hatred; so he has to be patient. So we advise your wife to be patient about the harm of her female colleagues and endeavour to face their bad deeds with kindness; may Allaah make her a means of their guidance to Islam. There is no harm for her to take the matter to her superior if she is sure that she will get her right from him/her, and if she is safe from getting a greater harm than the present harm. Finally, we would like to draw your attention to the following matters:
Firstly, in principle a woman should stay at home to do the housework and educate and take care of her children. However, if she goes out she has to observe the Islamic requirements among which is to wear the Hijab, and the workplace should be free of forbidden mixing with marriageable men (in case there are men in the workplace).
Secondly, it is more appropriate for your wife to leave this job if there is no need for it, because it is most likely that she will be harmed regarding her worldly life and her religion by socialising with such people.
Thirdly, when the Prophet feared a people, he would supplicate: "O, Allaah, we ask You to restrain them by their necks and we take refuge in You from their evil." [Abu Daawood]
Allaah knows best.