The reaction to Ultima's seeming miracle reflects the larger conflict between good and evil in the novel, and the deeper question of the source of Ultima's own powers. Members of Antonio's family are obviously quite happy, as Ultima has saved a relative from certain death. They are excited, and all thank Ultima and protect her as she leaves.
The other members of the town are described as a "curious, anxious crowd". They are fascinated by what Ultima has done, but are also nervous due to their belief in black magic. One of them shouts "la curandera", a label of respect. Some women are described as bowing their heads, also in respect. Yet others make the sign of the cross, which is traditionally used to ward off evil. Others shout "bruja", meaning witch. Thus the town seems divided on her true nature. Yet the last thing Antonio hears is "Es sin pecado", meaning "She has no sin." The fact that this is last suggests that overall the town agrees that Ultima acts for good, and has truly performed a miracle.