Let's view this from a scientific perspective:

It's quite possible that either one's mother, or less likely, grandmother, err... introduced! that's it... the distinctive genes shown, and now is when they popped up. I won't accept great grandmother as genes tend to be watered down over generations and it's more than just skin colour we see there.

It's possible. It's also possible someone took a photograph of a couple who adopted some black kids and wrote a fake news story to fit a narrative, or as psy-ops, but that will be caught out in time.

Or... well...