Mirabelle could be Mirabel couldn't it? Just as there are Isabelle and Isabel.
Mirabel is an airport in Montreal but I don't think that should bother anyone. The name means wonderous, which is pretty fab!
I like a whole set of M names; Miriam, Marianne, Mirabelle and also like alternative 'bel' names e.g. Christabel, now that Isabel, which I have loved for years, has become so popular, so I really do like Mirabelle!