Mia's enemies at home are, by definition, anyone who opposes or threatens the Magic Guild or Lunar. It sure made family life weird for a while. As far as personal Milliways enemies go, well, Draco Malfoy was almost her first and you can kind of see how that went. She's not fond of Scarlet at all, but I wouldn't call her an enemy since that would imply that Mia wishes her destroyed and she simply just doesn't want anything to do with her.

No one wants to be Mia's enemy, really. I mean, look at this icon. She's my own pup and she scares me with that.