How can I deal with a wife who neglects her marital duties due to her father's illness, and makes me feel that she prioritizes her father over me, while I wish to avoid hating her father?

The wife did well by responding to the marital bed, but she did wrong with her statement, which contradicts living together amicably, if she uttered it out of annoyance. Some scholars considered harsh words from a wife to her husband a form of nushuz (disobedience). Therefore, the husband should advise her and explain to her that her sadness does not justify such a statement, and he should not be affected by it.