Th13teen,TH13TEEN,thirteen or 13
That's probably the best one for her... It's enough of a ride to feel thrilling, and the indoor element is always a great surprise to people who don't know. But it isn't too much of a ride to feel intimidating.
But, if she wants to go a bit bigger, take her on air, not too fast, a relaxing and none intimating theme, but still a thrill ride, whilst th13teen is more of a family thrill. If she's been on the big dipper, Th13teen should be fine, and possibly air to.
Hope I've helped...