Sarah Harding, a member of the British-Irish music group "Girls Aloud," died Sunday morning at age 39 from breast cancer.

Harding's death was announced on Instagram by her mother, Marie. 

“It’s with deep heartbreak that today I’m sharing the news that my beautiful daughter Sarah has sadly passed away. Many of you will know of Sarah’s battle with cancer and that she fought so strongly from her diagnosis until her last day. She slipped away peacefully this morning. I’d like to thank everyone for their kind support over the past year. It meant the world to Sarah and it gave her great strength and comfort to know she was loved. I know she won’t want to be remembered for her fight against this terrible disease – she was a bright shining star and I hope that’s how she can be remembered instead. read the note on Instagram. 

In August 2020, Harding announced on Instagram that she has been diagnosed with breast cancer and that the cancer had advanced to other parts of her body.

"I’m currently undergoing weekly chemotherapy sessions and I am fighting as hard as I possibly can … My amazing mum, family and close friends are helping me through this, and I want to say a thank you to the wonderful NHS doctors and nurses who have been and continue to be heroes," her post read.

In her memoir, Harding said that her doctors had told her in December that her time would be short and that she would not see another Christmas. 

She claimed to have ignored advice to get the bumps under her arm checked out in December 2019. She said that a doctor eventually told her to get an MRI scan but the scan was delayed further due to the pandemic. 

“I was aware that I needed to get this health issue sorted, but with everything that was going on, it was tough,” Harding said. 

Her story explains that she knew she was in denial and that she needed to stop making excuses about her situation. 

“One day I woke up realising that I'd been in denial about the whole thing. Yes, there was a lockdown, yes, there was a pandemic, but it was almost as if I'd been using that as an excuse not to face up to the fact that something was very wrong," she said.

Girls Aloud was a five-member pop group that gained fame in 2002 from the talent show, "Popstars: The Rivals." Harding was joined by singers Cheryl Tweedy, Nadine Coyle, Nicola Roberts and Kimberley Walsh.

In 2015, Harding released"Threads," her only solo album. 

Harding dated television personality Calum Best from 2005 and had been engaged to DJ Tom Crane in 2011. She later began a relationship with DJ Mark Foster in 2012.

Harding entered a rehabilitation center in South Africa in 2011 for alcohol dependence and depression.

Many on social media paid tribute to Harding.