She was born approximately 3 hours before the exact conjunction. Traditionally New Moons and Full Moons are Astrologically significant events - New Moons mar the beginning of cycles and therefore have great potential. Traditional Months begin just after this point when the first crescent of the Moon becomes visible.
For the Moon itself, both the conjunction and opposition are seen as debilities, the New Moon conjunction is where the Sun blots out the Moon and it is invisible, the Full Moon is an oppostion aspect which is the strongest aspect of all (the conjunction is not strictly speaking an aspect).
So you have a niece who has great promise for development and even better the conjunction is also on her MC - the Sun is just approaching it's highest point in the Sky (which occured 27 minutes later. So the Sun and Moon have a lot of accidental dignity - it's a very strong placement.
it is really cool learning all that ..