I suggest a 134. If she will be getting taller, she will need a wider stance... and will probably feel more comfortable in a 134. I am 95 lbs and I ride a 132, but I can easily ride in a 134.
As for setups, here's one by Liquid Force that's great for learning but will keep up with you when you go to more advanced tricks (it's the same shape ben greenwood was riding before he got his own board) http://www.miamiskinautiques.com/2008-Liquid-Force-diva-with-Prima-boots-p/08lfdiva-fslash-prima.htm
And also, from Ronix, there's this setup that has an asymetrical board that helps you improve your TS edge. http://www.miamiskinautiques.com/2008-Ronix-Krush-with-Halo-Boots-p/08rnxkrush-fslash-halo.htm
Both boards are very light and would be great for her.
IMO the premier is a great board, but for my taste it is too slow and lands hard.