Numerologists believe the "perfect tens", which happen only once a century, symbolise a "powerful moment of rebirth". Some even claim yesterday was the luckiest day of the century, the Daily Mail reported.
She was born weighing just four pounds after being delivered naturally at eight weeks premature. A digital clock placed in the delivery suite recorded the time of birth.
Niamh's mother Keelie, 20, said, "When I looked at the clock and saw the ten seconds as well I was gobsmacked. It is certainly a date to remember and it is even more special as it is my first child. She is absolutely tiny and has tiny fingers. She is gorgeous."
She added: "I remember suddenly feeling the need to push. It was mad. Dean only arrived ten minutes before the head started to appear. It all happened so quickly." Dawn Grix, delivery suite coordinator at Good Hope Hospital, said Niamh would be kept in the special care baby unit until November because she was born so prematurely.