Catherine was born to Malayali Frank Mario Alexander and Tresa Alexander in Dubai. She said, “I don’t speak fluent Malayalam, it’s mostly English that we speak at home. I speak decent Hindi though and now I’m taking lessons in Telugu”. She did her Class 12 in Dubai and moved to Bengaluru for higher education. She studied for two years in St Joseph’s College, Bengaluru.
While studying, she pursued extra-curricular activities. She learnt to play piano, and got trained in singing, dancing, ice skating and debating, stating that she believes that she is “good at anything I put my mind to”. In Dubai, Catherine was an Emirates Environment volunteer. At the age of 14, Catherine did some amateur modelling for fashion design graduate students. After coming to India, she modelled for Nalli Silks, Chennai Silks, Fast Track, Josco Jewellers and Deccan Chronicle. She has also shot for Srikantadatta Wodeyar’s Maharaja Calendar and had participated with Prasad Bidapa in many ramp shows in many cities