It appears to be a French cognate of Spanish 'Miraflor.'
I've a friend of Hispanic extraction named Myraflor (a variant of the more common Miraflor) and she once said the name is derived from "milagrosa flordeliza." Granted this is an wholly unvarified derivation. Further, another caveat is my lack of in-depth knowledge regarding those peculiarly Spanish/Catholic naming conventions.
I hope this can start you off or draw in more astute minds than mine.