Christina was always looking for spiritual connection with God. Under Christianity, within the holy trinity, there are three persons accounting for God. Not convinced of those three demigods, Christina used to establish the stated connection with the Father, presumably the highest of the three persons constituting God.
However, when her family left the Catholic Church after a scandal involving a catholic priest and boys, a high school friend of Christina converted to Islam. Moreover, Christina was invited by some friends she met in Virginia. They let her know what Ramadan and fasting are, and they took her at night to the mosque.
Watch this video to know how prayer and fasting converted Christina to Islam.