I had to follow the muse on this one, who decided it was about having another child, for no "good" reason. Please don't hate me, this does not reflect my reasoning at all!
I will say that the seed idea was sparked by a controversial decision made by someone I know, though I took it to a preposterous exaggeration of the motivation.
I only have the two kids,
one's a girl and one's a boy
so I thought I'd have another,
just to cleanly break the tie
But the gods were out to lunch
and I have a nasty hunch
they feel, conceivably,
"Divide them evenly"
They seem to be against it
though my hon' and I have wished it
and we've done the work, quite diligently,
every night, not accident'ly
Meanwhile in the upper bedrooms
1 and 1 have awful tantrums
deadlocked in the tallying
though mom and dad are rallying
perhaps a mini one and mini two
should be enough, yes two should really do!
And neither one can say they've one of each,
(one has a) brother, and the other, just a sister (she's a peach)
A crazy mom paired with a nutso dad
this family of four will be the best they've ever had