What is the ruling of Islamic law regarding a girl who broke off her engagement, citing a lack of feelings towards the suitor, even though she was the one who sought the engagement and agreed to it based on her admiration for the suitor's religiosity and character?

It is impermissible to supplicate against a woman who has withdrawn from marriage, because her retraction from the promise of marriage is not an injustice. It may have hidden reasons or a change of heart, and there is no blame upon her even if her withdrawal was without cause.

The matter of marriage is in the hands of Allah Almighty, and Allah’s decree for the believer is always good. What happened may have been a good [outcome] that Allah averted from you, in accordance with His saying: "And it may be that you dislike a thing which is good for you and that you like a thing which is bad for you. Allah knows but you do not know."

The thought that she mocked you is an evil thought and a whisper from Satan, and you must be wary of his treachery. You did well by refusing to go out with her before marriage.