Eliza may be eternally pregnant, but that doesn't stop her from having contractions and bouts of labour as her body still tries to do what it was meant to. Eventually they fade away, but not before leaving her gasping for breath, sweat rolling down her skin from the exertion of her womb pressing against the four babies within. Luckily the strong bouts only occur about once every week or two, so she does get some reprieve between them.
My first gif animation was an overly ambitious one with a centaur that I never finished, so I kept this second one with Eliza simple to avoid the same mistake. I did color part of it, but stopped and settled for just black&white. I also have a newer gif of her in the works, which is more ambitious and cel-shaded. It's actually pretty far along: there's just one part left to make. (But a tricky part.)