What should the second wife do after twenty years of her marriage, given the first wife's refusal to acknowledge this marriage despite attempts to adapt and her rejection of adaptation even for the sake of the children?

Polygyny is one of the merits of Islamic Sharia. It is permissible under two conditions: justice and the ability to provide financial support. The first wife's non-recognition of the second marriage does not harm the husband or the second wife, nor does it affect the validity of the marriage. The second wife is advised to be kind to the first wife, but if that does not prove beneficial, there is no blame upon her. The husband is not required to seek permission from his first wife to marry another.