My point is that's not precisely correct. Chico/Chica "means" "little (one)", so it is often used when you might otherwise use a word that means more precisely "boy" or "girl". A source which says
Chica means "girl" is an oversimplification. Equivalent terms would include "mon petit/ma petite", "little one" or "littlun", although the french terms have different connotations depending on the gender (although I could see some overlap between the usages of chica and "ma petite"). I also have to wonder how much the spanish terms contribute to the sense "young child, girl/young woman" for the English word "chick"