The game itself is quite good, it is perfect for kids who are starting to like fashion and make up and stuff like that, not to say it is also great for somewhat older girls. There are lots of different treatments you can do with your girl and many combinations of both clothes and make up which creates a nice variety. I would have to say though the app is swell, after washing her hair and scrubbing her face with the same lotions for the 20th time, it could possibly get boring, unless your into that sort of repetition thing. Id suggest playing it once in a while, so the "being bored" thing wont be such a problem. Also more make up should be unlocked, especially because we cant use red lipstick, or some not-so-wild eyeshadow.
This goes for all the salon games made by this company, so I also suggest you get one that you really like cause they are pretty much the same as for the face.