What is the ruling regarding a girl who refuses to marry someone, but then learns that one of his relatives has bewitched her to marry him, and she is still suffering from symptoms of chest tightness, headaches, and trembling hands?

Accusing a specific person of sorcery without evidence is forbidden and requires repentance. The symptoms mentioned are not necessarily indicative of sorcery. However, if there is a strong presumption that it is sorcery, it should be treated with legitimate ruqyah (definition) (exorcism). As for marriage, you are not religiously obligated to marry someone you do not desire, and pressuring you to do so is religiously displeasing. However, if the suitor is religious and of good character, and you marry him seeking affection for the sake of kinship, we hope you will receive abundant reward.