Is a wife who suffers from her husband's severe beatings and his threats to take her children and deprive her of them, and his humiliation of her in front of them, despite her acknowledgment of his favor, considered ungrateful to her husband?

You must fear Allah in regard to your husband, be kind to him, and be patient with his harm. Try not to provoke him. You do not have the right to use his phone without his permission. You must remind him of the wife's rights, the importance of treating her kindly, and the impermissibility of striking her. Strive to obey Allah and supplicate for his guidance and for the removal of anger from him. Both of you should agree to refer to Islamic law in your disputes.