Is Poppy's youthful look a common thing, or is she special?

Been playing a lot of Heim lately, and it got me thinking about Poppy, weirdly enough. She's canonically over a millennia old, but she looks like the blue elf version of a 20 year old. While guys like Heim and Corki, who I doubt have been around for as long, look like old guys. We only have 2 other female Yordles to compare to, and one() is a weird case, cause she was in the Glade. TL;DR, you think all female Yordles retain their youthful looks like she does, or is she some weird special case cause of the hammer or something?