Olivia Wise, 16, died Monday, according to a statement from her family.
Earlier this fall, Wise released on YouTube and iTunes a cover version of Perry's song, with all proceeds going to the Liv Wise Fund supporting children with brain tumours.
The video has been viewed over one million times, contributing to some $85,000 for the fund. It is working towards a goal of $150,000.
Wise's recording prompted a thumbs-up from Perry herself, who commended the teen's performance and efforts in a brief video statement.
"I was very moved and you sounded great," said Perry.
The singer noted Wise's passing early Tuesday morning.
"I can hear you singing with the angels now," she said via Twitter.