As for kobolds, I understand that there is no substantial difference in the physique between the males and females (slightly shorter with thinner arms/legs/tail.) The subtle differences impossible to represent in miniatures.
Dragonborn and half-dragons; however, do have some gender-specific traits owed to their mammalian/ non-reptilian heritage (things that wiggle, things that jiggle, and things that dangle)
Any mammal-base or hybrid creature should theoretically possess physical attributes that are gender-specific, but weather or not the differences translate noticeably to miniature figures can be debated.
For example, something unique about gnoll/hyena where the female has a dangly bit that's larger than a male's, and how anthropomorphism effects the placement and how animal breasts function.
Often the simplest solution makes the most sense: just put a pair of breasts (as long as they have the torso to support them) since bipedal creatures would benefit more from a single set of functional breasts in both the evolutionary/survival aspect, and social aspect (whereupon they can coexist with other species of similar endowments more easily)