Is a girl permitted to refuse a man she was forced to marry against her will, and is it considered zina (unlawful sexual intercourse) if he forces her to do so?

It is not permissible to force a mature woman into marriage. If she is coerced, there is a difference of opinion among scholars regarding the validity of her marriage. The more preponderant opinion is that it is null and void if it was without her consent. So, if she was coerced and did not consent to the marriage, she has the right to refuse her husband and seek separation. However, if she consented and approved the marriage, it is permissible to act upon the opinion of those who validate it, and she must obey her husband if he calls her to bed, unless she has a legitimate excuse. It is permissible for the husband to compel her to intercourse if she refuses without a legitimate excuse. A man's cohabitation with his wife is not considered adultery, whether with her consent or by compulsion, unless there is a legal impediment.