I like it better in the mn spot. As a fn it makes me think of [name]Mariah[/name] [name]Carey[/name]'s [name]Monroe[/name] immediately. There could also be spelling confusion with [name]Munro[/name].
I really like it. I love when names have meanings or significance to the parents. Normally [name]Munro[/name] isn’t not my style, but in this case, being your maiden name, I think its very nice, and a cool connection to your family.