What is the ruling on shunning a son and his wife because the wife removed her hijab, and they insist on it, and is there another action that can be taken to solve this problem?

The hijab is an obligation upon the Muslim woman wherever she may be, and it is not permissible for her to be lenient regarding it. The husband is responsible for his wife and must oblige her to wear the shar'i hijab. He has the right to prevent her from going out if she disobeys, because Allah Almighty says: "Men are in charge of women by [right of] what Allah has preferred some of them over others and by [right of] what they spend from their wealth." And the husband's approval of her taking off the hijab is a sin and a form of dayouthah (cuckoldry/lacking protective jealousy). If the husband denies the obligation of the hijab, the matter is more serious and may lead to disbelief (kufr). Both of them must be advised with gentleness and wisdom. If advice does not work, then abandonment is permissible if benefit is hoped for. What is mentioned regarding the hijab is the covering of the head and the rest of the body. As for covering the face, the preponderant opinion is its obligation, though the matter is less strict and the difference of opinion on it is strong. Residing in lands of disbelief is dangerous, and emigration from them to Muslim lands is obligatory when the necessity or severe need ceases.