Hi,
I had a look at this on the Irish Civil Records website. It is possible that "Maid" is actually written in the wrong column of the entry, because in the next column under Rank or Profession, "spinster" is entered. So, yes, she could have been a servant.
Alternatively, whoever wrote the entry may have been emphasising the young lady's virginity, since the word "maid" commonly referred to young women who had as yet had no carnal knowledge of the opposite sex.