Three months later, Ms Mannering is home with her eight-day-old son Tyson, a moment she tells ITV News she was not sure she would ever see.
Ms Mannering, from Herne Bay, Kent, filmed her impassioned plea just after being told she had contracted Covid-19 and had pneumonia in both lungs.
"I genuinely felt as if I'd been handed my death certificate," she told ITV News.
"I was genuinely petrified.
"That's why I was just crying and crying."
She was desperate to get the message out to everyone that they needed to stay at home.
"I did feel quite angry towards them," she says.
"Why are they carrying on as normal?
"I'm here fighting for my life, and my baby's life and they're all caring on having a drink down the sea wall and meeting up with friends."
Tyson, her fourth child with husband Steve, appears unscathed by his ordeal, but Ms Mannering says she has never been as emotional as she was after giving birth to him.
"Emotional, really emotional, I felt as if, I've never been as emotional as what I was after having him, and I think it was everything," she says.
"I never really believed I was ever going to ever truly have him in my arms and we were both going to be together.
"It really was a scary time for us both, so it was brilliant to have him there, and the love that you feel, I feel like I can finally release rather than holding on."
Ms Mannering said it was "lovely" that after her video from hospital was widely shared on social media, people sent her messages of support.
"It was lovely, it was really nice to know that there were people out there who genuinely cared."