When a woman reaches 60 she becomes so angular she can't be drawn without poking your eyes out
Besides the implications toward older women of "twentysomething" being described only as "pretty all over" (with, apparently no advice on how to draw "pretty all over"), there's also that Forty and Fifty both look like the exact same 20 year old except experimenting with hair dye, and Twenty looks like her twin sister with a slightly shorter face. Anyway I think the "Fiftysomething" drawing actually looks like it'd be great for a Marvel What If about if Mary Jane Watson became Director of SHIELD.
(Excerpt from "Drawing Cutting Edge Fusion: American comics with a Manga Influence" by Christopher Hart)
Page text reads:
Twentysomething: "Pretty All Over"
Fortysomething: "The face becomes wider but also more angular"
Fiftysomething: "The face still becomes wider and more angular but the lips get thinner, and note the slightly forward-leaning angle to the neck."