The 24-year-old singer showed off her new bald look on a TV show appearance as part of Comic Relief, reported Daily Star.
"It's the weirdest feeling... It feels so liberating," she said.
The star has raised over 500,000 pounds for the cause after offering to shave off her long dark hair, and said the drastic haircut and the money fans had paid to will her on had really stunned members of her family, who were backstage at the telethon.
"Everyone's crying. My mum's back there, my mum's crying with happiness," she said.