How can an Australian girl from another religion be convinced to believe in the Oneness of God as quickly as possible?

It is advisable to remind people of what is ingrained in their nature concerning Allah's Lordship over creation and governance, and that He alone is worthy of worship. It should be explained to them that all Messengers agreed on calling to monotheism, and that polytheists are promised a painful torment, whereas monotheists will not abide eternally in Hellfire and will live eternally in Paradise. It should also be mentioned what Allah supported His Messengers with in terms of miracles, the greatest of which is the Quran, along with frequent seeking of Allah's help for their guidance. Men must avoid getting to know foreign women and should invite men, while women should be connected with educated women interested in da'wah.