What did Charlotte's leather bracelet come from?

When Charlotte’s parents die, she is found grasping the leather reins of the horses that were driving the wagon. The doctor who finds her cuts the reins and says “she might as well have something to hold on to […] she hasn’t got much else. There’s no other family to speak of” (4). She wears the leather rein as a bracelet for the rest of her life: “For as long as anyone could remember, she wore a strip of leather rein tied around her wrist” (5).