Seria "chica plastica" ? but this is better used for 'a vain girl'
I don't think there is such a wonderful phrase like "high maintenance girl" that this can be translated to in spanish, if you use any of the words given by the posters here, which by the way could probably all be used in place, you would probably have to explain exactly what you are trying to say, here is a more detail explaination of the phrase.
--------------------------------------------------------------------------------
High maintenance chick implica una chica de gustos caros, en la cual debes invertir adem?s de tiempo, mucho dinero. Implica que le pueden gustar los lugares caros, regalos caros; la apariencia antes que la sustancia.