Is it permissible for female teachers to instruct a group of male students, while unveiled girls are mixed in with them, in a government institution?

Mixing (of genders) and ostentatious display (of beauty, tabarruj) are prohibited calamities due to the great harms that result from them. It is obligatory to enjoin good and forbid evil, and to advise girls to observe modesty and hijab, and to instill the fear of Allah in them. A woman must cover her entire body, even her face and hands, when there is fear of fitna (temptation/strife). Students should be guided to understand the danger and harms of mixing, and those in charge of schools should be advised to fear Allah and recognize the necessity of separating young men and young women, and to obligate girls to wear hijab. If the situation does not change, then it is preferable to seek another school where there is no ostentatious display or mixing.