Mummy vs. Mommy

In England, we wrote Mum, Mummy. In North America, it is Mom or Mommy. I have a hard time keeping it straight some times when I write to my Mom in cards, email, etc. I tend to use Mom more often as, well, I’m in Canada now, but I am homesick for the old Mum. I remember Mom always signing my cards with “Mummy.” So very sweet. I love dat woman!