Looking for a book something about a girl replacing princesses?

I once read this book borrowed from a library. It's about this girl who has a job replacing princesses. She was in a bathroom reading the newspaper and saw this ad that said something about travelling the world and whoever wants the job should call this person. So she said the person's name out loud as she was frustrated that there was no number on the ad and she got the job. Like there is this bubble that she travels around and there is this 'foundation' that when she applies it on her appearance would change to the princess she is replacing and when she is replacing that princess, the time would somehow 'stop' so that she can still go on with her normal life. I want to read it again and it is supposed to be a series so I want to see if the other books have been written yet. Please, if you know this book, tell me the title. Thank you.