I understand that PG (Kara Zor-L) was rocketed from Krypton-2 as an infant, at the same time as the infant Kal-L. Her spaceship just took a lot longer to arrive on Earth-2. By contrast, Supergirl (Kara Zor-El) left Argo City as a teenager and didn’t age much during her trip. Therefore, I guess it’s possible that their different environments (suspended animation in a spacecraft vs. artificial gravity on an asteroid) would have made Power Girl bustier and more muscular than the comparatively willowy Supergirl. PG would have also been exposed to a greater variety of stellar and cosmic radiation than her counterpart. The Earth-2 Supes is beefier than the “regular” one, as well.
So, has everyone already figured this out? Am I that slow on the uptake? Could this justify more naturalistic proportions on both characters, or is the appeal of artistic license too strong?