Sarah Harding's Girls Aloud bandmates Kimberley Walsh, Nadine Coyle and Nicola Roberts have sent their birthday wishes to the star, who turns 39 today.
Leading the tributes, Kimberley shared a selection of throwback photos following Celebrity Big Brother winner Sarah's devastating advanced stage breast cancer diagnosis earlier this year.
She said, "Happy Birthday to our blonde bombshell and my fellow scorpion @sarahnicoleharding ... love you so much ❤️❤️❤️".
Adding their birthday wishes, former I'm A Celebrity...Get Me Out of Here! star Nadine Coyle simply commented '❤️❤️❤️❤️❤️', with Nicola Roberts adding '@nadinecoyle @kimberleywalshofficial ♥️♥️♥️♥️♥️'.
Fellow Girls Aloud member Cheryl is yet to comment.
Back in August, Sarah announced the news of her cancer diagnosis to fans on Instagram. She wrote, "Hi everyone, I hope you are all keeping safe and well during these uncertain times.
"I've not posted on here for so long, thank you to everyone who has reached out to check in on me, it really does mean a lot.
"I feel now is the right time to share what's been going on. 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."
Sarah continued, "I'm currently undergoing weekly chemotherapy sessions and I am fighting as hard as I possibly can. I understand this might be shocking to read on social media and that really isn't my intention.
"But last week it was mentioned online that I had been seen in hospital, so I feel now is the time to let people know what's going on and this is the best way I can think of to do so.
"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."
This comes after Kimberley recently revealed she and her Girls Aloud bandmates are speaking to Sarah 'all the time' following her diagnosis.
She said, "I am completely devastated, it's been really, really tough, but speaking to her a lot helps and keeping that contact.
"She’s a strong girl and I love her so much."