What is the ruling on a wife's insistence on changing her daughter's name from "Zaynab" to "Malak" after two years and three months, and her threat of abandonment if her demand is not met, and what should the husband do in this regard?

The wife does not have the right to demand a change to the name the husband chose for their daughter, especially since the name is good, like naming one of the Prophet's daughters (peace be upon him). Furthermore, the name "Malak" (angel) is questionable. If the wife insists on creating problems or leaves the house without the husband's permission, she is disobedient (nashiz). However, if an agreement can be reached on another permissible name, that would be better, as the matter is simple and should not lead to such a level of disagreement.