Well, I really did get it wrong! I had no idea. Here is a memory from Rod Stradling.

Meg Aitken: Meg was a busker who Danny first heard singing in Villiers Street, outside Charing Cross Station. She went on to sing As Long as he Needs Me on a record of London buskers, and we believe her accompanist on The Last Thing on my Mind at the club was Don Partridge, who was also on the buskers record. Unfortunately, the recording of that is terrible, so we've got Danny Boy instead.

We know nothing about her, but while looking for at least a photo, (which we didn't find) we discovered, from her grandson, online, that her name was not Aitken but Aikman. Whoever she was, the singing is blinding!