There are not, as a rule, many kids on B5. They are more the
exception than the rule, and even there mainly traveling to or from one
place to another with their families. This is not a place where you come
to raise families; it's a way-station, not a destination. And given the
fates of B1-B4, nearly everyone who chooses to come work there has left
their families for a period of X-years to earn fairly good sized salaries
working B5 (hazard pay and all that).

Hybrids are impossible in the B5 universe without direct genetic
alteration. You can't just have casual mating. Interspecies sex may
present opportunities for exploration, but the chances of a Narn
impregnating a human are about the same as a human impregnating a fish
and producing a motorcycle.

jms