Caine was born on 23 September 1966 at Crown Street Women’s Hospital in Sydney, Australia.
On March 30, 1996 Caine married Nicholas Joseph Caine whom she met at Hillsong Church in Sydney, Australia.
One week before her thirty-third birthday Caine discovered she had been adopted.
Her brother phoned her with the shocking news that he had received a letter from the Department of Community Services (DoCS) notifying him that he had been adopted at birth. Initially believing it was a mistake, Christine asked her brother to phone DoCS. DoCS confirmed the letter. Their mother also confirmed George’s adoption, and went on to tell Caine that she too had been adopted. Because the system laws had been so different, Christine’s parents believed that she and her brother would never find out. After her initial amusing response, "am I still Greek?!" Caine responded well to the news, and quoted scriptures she had been meditating on from Psalm 139:13-16.
Caine maintains a strong sense of personal identity within her Christian faith, and remains close to her adopted mother and brothers. When Caine was 19, her father died due to cancer.
Today Caine lives in Baulkham Hills, Australia with her husband Nick. Together they have two children, Catherine and Sofia.