Is it permissible to continue supplicating for a non-Muslim girl, asking for her guidance to Islam, out of fear for her from the Hellfire, knowing that the noble verse says: "Indeed, you do not guide whom you like, but Allah guides whom He wills. And He is most knowing of the [rightly] guided"? And is it permissible to do anything else, such as giving charity on her behalf?

As for your prayer for the girl's guidance, there is no harm in it. Her guidance is left to Allah alone, so do not grieve yourself to death over her if she does not believe, following the example of the Prophet (peace and blessings be upon him), whom Allah forbade from excessive sorrow over the disbelief of his people.

We advise you to be cautious about communicating with non-mahram women due to the great temptation therein, as the Prophet (peace and blessings be upon him) said: "I have not left behind me a trial more harmful to men than women."

If you are able to marry, then hasten to do so to protect yourself and keep it away from temptations, and seek a righteous woman of religion. If you are unable to marry, then avoid arousal-inducing things, fast, accompany the good, and fill your free time with what benefits you in your religion and your worldly life.