But a woman with a "boyish" figure as was popular in the 20s and in ancient Egypt would not have a low WTH ratio - otherwise they wouldn't look boyish. And then there's this - which I've already said but am reiterating:

"Younger women are more likely to have an hourglass figure, and age is related to fertility, but the most attractive waist-to-hip ratios are generally found in women in their late teens, whereas women’s fertility tends to peak in their mid to late twenties."