They sure are cute. I have one that is over 4 months old and still can't figure out definitely if boy or girl

HI everyone .
Out of the 20 eggs I got 2 that hatched a light one and a dark one . They are about 4 weeks old can we sex them yet ?
Here is the dark one this one is more mellow the other one attacks my fingers![]()
This is the light one and the finger eater. Are sweedish flower hens sapose to be flighty or aggressive ?
Anyways can you tell at this age if these are males or females and is there a reason they are so diffrent?