The 80-year-old woman who discovered the Cross upon which Jesus was crucifiedSt. Helena did travel around the Holy Land looking to locate relics and sites associated with Christian origins, but Eusebius doesn't refer to her finding the true—or any—cross, and the story only surfaces a generation or two later, so it should be taken with a good grain of salt.
St Helena (August 18), the mother of Constantine, became celebrated for her charity to the poor and to prisoners
By Spiritual Life on Monday, 15 August 2011
Helena (c 249-c 329) was the mother of Constantine the Great, the first Christian emperor. She is held up to reverence as the discoverer of the Cross upon which Jesus was crucified.
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In any case, the article has some interesting background on her.