Sandry's Book

In this book, the four principle characters of this series - Sandry, a young noblewoman, Daja, a Trader trangshi, Tris, a crazy girl, and Briar, a street rat - are introduced. They are taken to Winding Circle, the center of magic in whatever country they live in (I don't own the first two books). The mages there test them for the Gift, but find that they possess a power of a different kind - what Pierce calls "the craft magics."

So they end up going to another place, the name once again escapes me, where they are under the care of Dedicates Lark, Rosethorn, and Niklaren. They find out quickly that Briar has an unusual affinity with plants, Daja with metal, Tris with weather, and Sandry with any kind of fiber.

When an earthquake strikes Winding Circle, and the four are trapped in a cave underground, their only hope is to combine their powers. And so Sandry does with her spinning skill, creating the Circle of Magic.