Should the wife adhere to her hijab, which her husband rejects and threatens divorce over, or should she consider the future of her children and remove her hijab?

You are advised to strive in convincing your husband to accept the hijab, and to explain that it is an obligation and that his responsibility necessitates him being a helper. If he persists in refusal, then it is not permissible to obey him in removing the hijab, even if it leads to divorce. Trust that Allah will compensate you and your children, "And whoever fears Allah - He will make for him ease in his affair."