Although Guadeloupe is predominantly Black and she is likely regarded as a mixed woman, woman of color, or Black in Guadeloupe, Marie-Laure's family is West Indian (Caribbean) of East Indian descent (surname: Mahabir). East Indians are very common in the Caribbean and are perhaps the second largest ethnic group among the Black population, third being Latino (Puerto Rican, Dominican, Cuban). People of the West-Indies typically identify themselves by the islands they reside on and not so much by race, with the exception of Latinos. In fact, they commonly use terms to describe skin tones or ancestry to identify someone e.g. "Coolie", which is what Marie would be considered.
Technically she is Black, especially by West and French Indian standards, or a woman of mixed race (Black and White) if we go back further in history to the rise and fall of the Dravidian's (ancient Black civilization) in Asia/India, which resulted in the Indian (mixed) people we see today, but that's another topic. Essentially, she is Ebony.