I would like to mention a few authors you know and others you may not. The main character in almost every story listed is a young woman in her teens. One aspect that each girl has common with Crystal is an independent, feisty nature which comes in handy when encountering difficult tasks, although it may also get them into trouble. I hope you enjoy the following recommendations.

Twilight by Stephenie Meyer www.twilightnovel.com Aurelia by Anne Osterlund www.anneosterlund.com
Sabriel by Garth Nix www.garthnix.co.uk The Fire and The Light by Tracy A. Akers