The singer topped the charts with 'Wear It Like A Crown' and funds will go to The Christie Foundation NHS hospital in Manchester.
The 39-year-old revealed last year that she had been diagnosed with breast cancer.
The Girls Aloud star has died aged 39 following a year-long battle with breast cancer.
Little Mix shared their Brit Awards Best British Group victory with girl bands who had been nominated before them.
The Girls Aloud star said the book she's been writing in treatment was set for release next month.
The Girls Aloud singer won the show but revealed she had a minor panic attack in her first dress rehearsal.
The former girlband member was confirmed to be Queen Bee as she won the ITV singing show.