Can God answer a girl's prayer to marry a committed young man whom she loved, especially after they agreed to separate for fear of God's wrath, and how should she pray to achieve that?

If a supplication fulfills its conditions and manners, it is worthy of being answered. It is beneficial for the servant in this world and the Hereafter. On the authority of Abu Sa'id al-Khudri, the Prophet, peace and blessings be upon him, said: "There is no Muslim who supplicates with a supplication in which there is no sin or breaking of kinship ties, except that Allah will grant him one of three things: either He will hasten his supplication for him, or He will store it for him in the Hereafter, or He will avert from him an equivalent amount of evil." There is no harm in supplicating for marriage to a specific person, but it is better to supplicate generally for a righteous spouse, because a person does not know where the good lies for them.