I was not quite satisfied with the ending, but I don't know how to
better end it.
If you go the comedy route, I had a thought on that.. first perhaps
the two children should be born closer together.. rather than have
the whole forcing Kasumi to perform surgery thing perhaps Akane was
just told it was "unlikely she would ever conceive" rather than that
it was flat-out impossible... then Akane could have worn Ranma out
with her attempts for that miniscule chance. Anyway, it could end
with the two children acting like little Ranma and Akane reborn..
the boy could say something along the lines of "Hey that's mine. Not
a girl's toy. Look mommy, she's a tomboy!" and then have the little
girl hit him on the head with the little plastic mallet she was
playing with. :)
-Rain