What did Saint Lucy contribute to the Church?

All that is really known for certain of Saint Lucy is that she was a martyr in Syracuse, Sicily, during the Diocletian persecutions of 304 AD. Lucy is venerated as a saint by the Roman Catholic, Anglican, Lutheran, and Orthodox Churches. Early hagiographers have so embellished her life story that little, if any of it, can be taken seriously. Though the stories of her life cannot be regarded as accurate, there can be no doubt of the great veneration that was shown to St. Lucy by the early Church. Therefore, it is impossible to give a meaningful answer to your question.