Hi! I've seen people here (I'm also in South Africa, hence the -za in my handle) using Marié instead of Marie to indicate that the second syllable is emphasised (the assumption being that the -ie makes the Afrikaans sound); this wouldn't be necessary in French, where it would indicate a different sound for the -e, probably mah-ree-eh (eh as in let), so they would just see it as bad French. There's a lot of that going round in SA names! I've actually met a (male) Fransua and a (female) Chantel.
But, if it's your mn, you'd be the only one to know. Which could be a good reason to change, or not to change. Not much help, I'm afraid.