All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Parents have a great status in Islam and their children are obliged to be kind and dutiful to them, if we suppose that parents mistreat their children, they are still not allowed to mistreat their parents. In this regard, please refer to Fatwa 87019.
So, you should not mistreat your father even by the least kind of being discontent with him, which is saying a word if disrespect to him as this is a form of cutting relations with him, which is a great major sin.
Since it is an obligation to obey the parents, the children are obliged to obey them as much as possible as long they do not order them to disobey Allaah and as long as this does not cause them any harm which they can not bear. So if your father orders you to divorce this woman, you are not obliged to obey him, but if it is possible to divorce her in order to please you father then this is good, especially that marrying a woman of the people of the book has many disadvantages especially at this present day and age.
For more benefit, please refer to Fatwa 85876.
Allaah Knows best.