Debbie Ryan is a main waitress role.
There is also another poolside waitress that happens to be my cousin but my mother can't remember her name. She thinks it's Christy or Chrissy. My aunt said she filled in for the Candy counter girl in the original Suite Life but Maja Iven Ulstrup is not listed in Suite Life on Deck and I don't believe that's our cousin's name anyway. Would love to have that name to add to this answer.