Most Christian churches today teach that the OT law has been abolished and has no validity for Gentile Christians today. I'm not going to discuss whether that's true or not here, as it's being discussed on another thread. But it is rlevant here, since it has had the unfortunate effect that Christians no longer study the law of the Old Testament and, as a result, often don't understand what is being said in the New Testament. This is one example. Here is what the law has to say about it.
When a man hath taken a wife, and married her, and it come to pass that she find no favour in his eyes, because he hath found some uncleanness in her: then let him write her a bill of divorcement, and give it in her hand, and send her out of his house. And when she is departed out of his house, she may go and be another man's wife.
And if the latter husband hate her, and write her a bill of divorcement, and giveth it in her hand, and sendeth her out of his house; or if the latter husband die, which took her to be his wife; Her former husband, which sent her away, may not take her again to be his wife, after that she is defiled; for that is abomination before the LORD: and thou shalt not cause the land to sin, which the LORD thy God giveth thee for an inheritance. (Deu. 24:1-4 KJV)
In Jesus' day there was some debate about how to interpret these verses. Some interpreted the words "some uncleanness" to mean sexual sin, while others believed it could be applied to anything the husband didn't like about his wife. This is what the Pharisees were referring to when they asked Jesus whether a man could get divorced for any reason. They were asking for Jesus' interpretation of this passage of Scripture, and that's what he gave them (and, being who he was, his interpretation was the correct one). He said that it applied only to sexual sin. Any other reason is invalid. That's all he was saying. He was answering the Pharisee's question, not trying to restrict women's rights, neither with regard to remarriage, (the law assumes she'll get married again) nor with regards to getting a divorce from their husbands.
Although Jesus didn't address whether a woman could divorce her husband (since that's not what they were asking about), Paul did.
If any brother hath a wife that believeth not, and she be pleased to dwell with him, let him not put her away. And the woman which hath an husband that believeth not, and if he be pleased to dwell with her, let her not leave him.
For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy. But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases (I Cor. 7:12-15 KJV)
Paul tells us that we shouldn't ask for a divorce, but says that if an
unbelieving wife asks her Christian husband for a divorce, then the husband is "not under bondage".
So, to answer your question: Yes, a wife can divorce her husband, and do so in accordance with Scripture, but only if she isn't a Christian, or if her husband has cheated on her. The same applies to men divorcing their wives. Also, according to Scripture, if you do get a divorce because of adultery, then you're not allowed to marry your ex if she has married someone else and gotten a divorce from him. (It's not explicitly stated, but I believe it's in keeping with the spirit of Scripture that the same applies to women remarying their ex-husbands who have married and divorced someone else.)
