"Some parts of this stranger-than-fiction experience are still very vivid.
"I remember so clearly lying down, seeing the ankles of commuters around me and knowing what was about to happen.
"I remember the feeling of Louis' limbs rushing out of my body. I remember trying to tell everyone that he had been born into my pyjamas — "he's here!" and the incredulous face of my husband. Then press Louis against my skin.
"I don't remember getting up off the pavement, the cheers of strangers declaring 'it's a Christmas miracle!', the faces of the people, or who wrapped us up."
Mrs Hines said kind-hearted and quick-thinking strangers leapt to her aid — one fetched her a wheelchair and an off-duty doctor fought his way through the crowd to declare Louis healthy.
"Some people from the crowd found us later in the hospital which is a bit of a blur, one was a happy weeper from Venezuela."
Mrs Hines also said there was a "longer tale" concerning why she was turned away from the hospital, adding that it was a "thorny issue" of how women are cared for in the stages of early labour.
Lizzie wrote: "But thankfully Louis was absolutely fine and this was a euphoric and beautiful birth, and a strangely festive entrance!"
The grateful mother is now trying to get in touch with the passerby who lent her their scarf.
"So, the scarf. If you can share this pictured I'd be very grateful (here's me and Louis on the street, and Louis snuggling in it now.)
"It feels like a fitting week to return it and introduce my babbling, toddling baby to a member of his welcoming party."
A statement from UCLH to Buzzfeed said: "After Mrs Elizabeth Hines gave birth last December, we carried out an internal investigation so that we could learn from her experience and reduce the risk of it happening again.
"We have also apologised to Mrs Hines."