McCollin's netball career commenced from a young age. Born in Trinidad and Tobago to sports-coaching parents, she was selected to play for the under-16 international team at the age of 12, and rose up the international ranks to make her senior debut for the national team in 2015, at the age of 17. She has represented Trinidad and Tobago at the 2015 and 2019 Netball World Cups.