Assalamualaikum I find that whoever doesn't like the law of Allah is a disbeliever. We all know that polygamy is allowed by Allah. But most of the married Muslim women don't want or like their husband to take another woman. Does it make her out of Islam or disbeliever?
No the permission for polygny is bound to certain conditions which no normal human being is able to fulfill to 100%. That's why Allah added the words like "if you fear"(see in 4:3).
Secondly it is human nature that a wife wouldn't like to share her husband and Allah knows his creation best.
Finally scholars consider the condition of being the lonely wife added in a 'aqd nikah as valid.
So there's no reason considering opposing this per se as kufr. Unless a woman says Allah is unjust by ordering or allowing this.
No never ..it is nature of every woman has Jealousy and like her husband for her only ..and another woman shares her in him ..so you are true muslim and woman ..dont worry this is normal ..also there are conditions for ur husband if he likes to get married another ..he shuld be ajust and there is good reason make him get married ...if cant accept another woman in ur life ..u can ask divorced from him ..this is ur right ..if u have power to live with him you contiune