"Justine always had a smile on her face and was always happy to help others," Mr Cantor said. "One of her highlights was when the Special Olympics came to Cardiff. She was so pleased and proud to be asked to take part in helping with the project. She had a beautiful singing voice and loved to act."
Tribute was also paid to her by the 22,500 crowd at Cardiff City's match against Bristol City on Sunday.
Earlier this month, the JC reported on the family's efforts to raise money for the Velindre centre in Cardiff where Ms Cantor received treatment.
Her brother Elliott and sister Natasha used Twitter to contact dozens of footballers, celebrities and politicians to raise awareness of the centre's work.Their campaign has now raised £7,000.
