Happy Mudders Day

Have any of you heard Amber Chia's radio advertisement for a massage chair? She's a pretty woman, but it was clear from her English that she was Chinese-educated. Most funny was her pronounciation of "mother" - she said it "mudder". It was funny because I committed the same offense last time. While practicing for a debate in school years ago, my debate teacher commented on how I would say "mudder" instead of "mother".

Which brings me to another language concern: is it Mothers Day, Mother's Day, or Mothers' Day? Grammatically, all three are correct in different context. Of course, for Amber Chia there's no confusion as it has always been Happy Mudders Day.