Well, "White' in the Caribbean is mostly defined in a different way than 'white" in the USA or here in Australia. It depends more on your skin colour and appearance than your actual racial heritage. You can be considered White and still have Black ancestry. I have a friend whose great-grandfather was Melanesian Black, but who considers herself and is considered White because she looks White. So Cordelia could be considered White, but she probably still had some African ancestry- a middle-class Jamaican girl.
And Grishka, why would her head be red if it was meant to be her face? Surely then it would be 'Wha mek yu face so red" instead of "head".