Sarah, 38, revealed on Wednesday (26.08.20) she was diagnosed with breast cancer earlier this year, and she recently learned it's already advanced to other parts of her body.
And after sharing the sad news on social media, her former Girls Aloud bandmate Nadine, 35, has offered some words of support to her pal.
Commenting on Sarah's Instagram post, Nadine wrote: ''I love you!!!! You have always been able to achieve miracles when needed!! I am here for the all the way & always will be!!! (sic)''
Fellow Girls Aloud member Cheryl, 37, also appeared to pay tribute, as she simply tweeted a broken heart emoji just moments after Sarah's post was published.
However, Sarah has also received supportive comments from her other pals in the showbiz industry.
Steps star Ian 'H' Watkins wrote on Instagram: ''Sending HUGE [hearts] Stay Strong xx We're all behind you xx (sic)''
Whilst Fifi Geldof, the daughter of Bob Geldof, added: ''Oh my angel... I'm so sorry to hear this awful news!!! Fight hard and look after yourself - please shout if I can help at all. Much love to you (sic)''
Sarah announced the news of her cancer diagnosis on both Twitter and Instagram alongside a picture of herself in a hospital bed.
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.
''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. (sic)''
Sarah also thanked NHS ''heroes'' for their support over recent months and promised she'd ''keep positive'' amid her cancer fight.
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