Shadow (Shadow & Dagger #1) by Anne Logston - Vintage Paperback

Never trust an elf, a thief, or a woman. Shadow is all three... Shadow, a light-hearted (and light-fingered) elven thief, returns to her homeland after several centuries' absence only to find that a great human trade city has grown up next to the forest in which she was born. Now the elves and the humans maintain an uneasy alliance, but when Shadow steals a magical bracelet, she finds herself caught in the middle of a plot that may tear the city-and the alliance-apart forever.