She looks like she is straight from Ghana or Nigeria...
There is NO mix in her...Once you introduce non-black genes, they never go away...
Look at Bob Marley, he was half white and half black, he had children with Rita Marley, who was as dark as midnight, and all his children are "Light skinned"...
Black people who have even a little non-dark DNA in them, don't look the same as "pure" black people...
For example, Black Americans don't look the same as Black Africans...For the most part...
I know a mixed guy with a lightskin wife and their kids are darkskin.