Is the wife considered sinful if she refuses to emigrate with her husband and children to a non-Muslim country, or to travel to her insecure home country, especially since they live in the UAE, and her husband works and has a high salary?

Refusing to travel to lands of disbelief (Dar al-Kufr) or unsafe countries is permissible, and there is no sin in it. It is not permissible for the husband to emigrate to lands of disbelief, nor is it permissible for the wife to assist him in that. Rather, she should advise him and remind him of the danger that poses to the children and their upbringing, and the risks entailed by residing there, such as a Muslim sometimes being unable to observe the rituals of his religion and being compelled to abide by man-made laws. The husband should appreciate his wife's keenness on raising the children and help her in that, and he should thank Allah for His provision in a country where he can practice his religion.