I must admit I do not like this idea. I'd MUCH rather see gender showing on boxes like suggested in another thread.
One reason is the suggestion to make this once-in-a-lifetime... So ok, I get a kitten, do a gender-change, and a month later I sell it on an auction to someone who'd also like to gender-change it, but... OOOPS, previous owner already did! -To not mislead new owners, the previous gender-change should then show in stats... and now it starts getting really complicated!
Nah... gender on boxes, I say. I will have plenty of "please be a girl!"-moments anyway, while waiting for said box