Sarah Harding has passed away. The 'Girl Aloud' singer was just 39. Her mom herself confirmed the tragedy on an emotional Instagram post.

According to her mom, Harding had battled bravely her breast cancer. She ultimately lost but she can praised for keeping her diagnosis a secret so that others would not worry about her.

"It's with deep heartbreak that today I'm sharing the news that my beautiful daughter Sarah has sadly passed away," her mother wrote. "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."

The singer reportedly told her fans about illness only in August through an emotional phone call, when her cancer already spread. She kept her fight for months, so none of her bandmates knew.

Girls Aloud
Dave J Hogan / Contributor/ GETTY IMAGES

At the time the singer allegedly, said: "I'm doing my best to stay positive." The bandmates immediately rallied round her after she shared the devastating news she had ­cancer that has spread through her body.

Fans followed suit when she broke the news. She vowed to fight the cancer, while her mom. 80, acted as her main caregiver.

Support messages flowed in from fans and other celebrities alike, after she wrote this last year, "There's no easy way to say this and actually it doesn't even feel real writing this, but here goes. Earlier this year I was diagnosed with breast cancer and a couple of weeks ago I received the devastating news that the cancer has advanced to other parts of my body."

"I'm ­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. I am doing my very best to keep positive and will keep you updated," she added.

After her bandmates found out about the devastating news, they all individually released emotional messages. A source said this is quite expected, as they all have a deep and long history with each other.

"There is so much shared history between them all and to hear this from Sarah was utterly heartbreaking. They adore Sarah and are with her every step of the way," the source added.

"They've all shed a lot of tears but all of the girls vowed to be strong and be there for her no matter what. They are closer than ever as a unit," the source concluded.