Martial Artist/Assassin/Mage/Mist...seems to be getting a little complex for a newbie. You could consider the Shadowdancer
Morg and Gentry created, if you're willing to go outside the books it's perfect for the concept of an assassin that isn't the Assassin class. Monk 4 will get her sneaky skills, 2 combat feats, the ability to shrug of a grade of fatigue, and a nice refresh roll (handy for an elf) and reach +1 which is great for striking from the shadows and helps to keep her from going toe-to-toe with anyone.
Shadowdancer is tricky and mobile letting her hit and run and comes with a shadow the same way Infernalist comes with an Imp. That gives her a nice RP option, maybe it's the ghost of her brother who was killed in the slave camp by land dwellers. She's the only one who can see or hear him as his urges on to seek out and take vengeance killers so he can find peace in the after life.
Also, Knife Basics (with daggers or any other knife with the hurdle upgrade) goes great with the Hurled Basics chain, as you need to spend handle item actions.