We need more background? Is your dad and his wife from the exact same ethnic background? Are they urban or rural dwellers? Does your stepmom have access to non-African men? Do the children look like the typical half(Insert your ethnic background)/half white phenotype??
yeah same ethnic background
they live in a multi cultural city
and no, the kids dont have that typical biracial look
they actually literally look southern European lol
if you were to see them walking down the street, you would assume they're Italian or Spaniard or something....
also, the age time frame is pretty interesting too....
like I said, its three kids.....11, 6, and 3
the two youngest ones are the ones that dont look black....
which might be of note, because there isn't that big of a time gap between the 3 and 6 year old
and that might suggests that "it" happened in the same time frame