No, no, no. That's not what I'm saying. Clementine is a Black person! Her race is Black. Her parents are Black. But even though her parents probably identify as Black people, they're not 100% Sub-Saharan African. Because rape of Black women was so common in the 18th and 19th centuries, most Black people are at least partially European. Some have a lot more European ancestry than others. This is why you have Idris Elba and you have Beyonce. Both of those people are still Black. Their race is Black. But Beyonce has some really old European ancestry, while Idris Elba probably does not. It's possible that somebody like Clementine's mother might be more European than SSA. But she's still Black.
Let's say that Clementine's father is 75% SSA and 25% European. Clementine's mother is 25% SSA and 75% European. This makes Clementine 50% SSA and 50% European. She's still a Black person, of course. But she's a Black person who happens to be about an equal mix of SSA and European. Race and ethnicity aren't the same thing at all. Race is a cultural concept, and all based on personal identity and societal rules.
Neither of Clementines parents are white. It's possible none of her grandparents are white. She is a Black person, but happens to have more European ancestry than most Black people.