The mum-of-one, 36, delivered the news to her some 613,000 Instagram followers.
She explained that both her mother and her grandfather have been seriously ill in hospital.
Thanking the NHS, she said that her mother had had to receive emergency surgery.
Meanwhile her grandfather remains in hospital.
Sharing a picture of a pair of hands wearing medical gloves, she wrote: "It’s been a horrendous 6 days.
"Like nothing I've ever known"
"Mum was admitted to ICU on Friday night, needing emergency surgery. The worry was like nothing I’ve ever known. I want to take this opportunity to express my never ending gratitude to our #NHS and to #SalfordRoyal Hospital.
"The doctors worked around the clock to treat my mum swiftly and keep her protected from#covid19 at all times. In the six days she spent in ICU she witnessed heartbreak and miracles.
"Each time I spoke to her, [she described] the medical staff as ‘angels’. My mum has spent a week of her life with the greatest of heroes.
"Today I received the miraculous news that I could take her home. I’ve never felt more gratitude in my life. I for one will be continuing to ‘give thanks’ and prayer each Thursday - past lockdown to all the heroes still fighting, to all the hero’s we’ve lost and to all the families unable to be with loved ones.
"Don't stop giving"
"My grandad still fights for his life in the very same hospital. Unable to see him is heartbreaking, but knowing he is surrounded by ‘earth angels’ is reassuring.
"Do not stop giving. Do not stop hoping. Do NOT stop clapping. Do NOT stop praying. Do NOT stop counting small blessings. Stay safe. Save lives.
"There IS a pot of gold at the end of the rainbow. Welcome home Mum."
Her words come just weeks after she said both her parents had tested positive for coronavirus.
She also said she believes her husband, Tom Pitfield, suffered with the virus months ago.
Users flocked to send well wishes to the actress on Instagram.
Radio host Jenni Falconer wrote: "Such a relief to be able to take your mum home, let’s hope your grandad will be home soon too. Sending lots of love."
Fellow Strictly star Michelle Visage posted: "Sending you love my angel."
And her former Corrie co-star Samia Longchambon wrote: "So pleased she’s home for you Cath xxx."
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