This is off topic, sorry, but how is a strong jawline a "European" feature? I have a big pet peeve with people using whole continents to describe anything. "Asians" aren't the same, "Europeans" aren't the same, "Africans" aren't the same. I don't feel culturally or in any way associated with people from, say, Britain or Germany or France or Spain. And my jaw isn't even strong. Most people, where I'm from, have very round faces.
Also, Nikki and Heidi are both 100% Caucasian, as are most of us "Europeans", so I don't understand how you bundle up all European features yet make a difference between Nikki and Heidi, both basic white girls...
Lol, why does that bother you so much? It's pretty common knowledge that eastern europeans* (probably should've been more specific) have very strong facial features such as a strong jawline and high cheekbones. Nikki has a softer face than Heidi. There are physiological differences between the two that are probably reflected by their genealogy. These features are typically associated with countries such as Germany, Estonia, Balkans, Russia, Greece.
You can actually determine facial structure (to some degree, epigenetic variables play a role) from someones DNA: http://journals.plos.org/plosgenetics/a ... en.1004224
. Curvature, facial structure, etc all are notably different between those with different genetics. Which, coincidentally, contribute to the presence of strong or soft jawlines, fat distribution in the face, skull size (and thus proportion of forehead-height of cheekbones/depth of cheekbones-length and width of face).
So yeah, there are probably some differences. Not EVERY WHITE PERSON has the same features. It's likely Heidi has an eastern european/russian background given her facial structure.