St. Gertrude the Great

Saint Gertrude, Virgin, Mystic, and Benedictine Abbess, was called by Our Lord Himself, "My chosen Lily", and the Church has given her the title of "Great" although she is not counted among the Doctors of the Church, at least as of yet. She is the only woman Saint to have been accorded this honor. There are four St. Gertrudes, one of whom was the Abbott of the monastery when Gertrude entered there at five, so it is an added blessing that she is distinguished by the term Great, for our sakes, because there is one less opportunity for confusion. It ought to come as no surprise that she was born in that great age of Saints, the 13th century, among which are numbered St. Thomas Aquinas, St. Elizabeth of Hungary, and in the later years of which, both St. Francis of Assisi and St. Dominic, the latter two being born in the 12th century. Not only was this century the "Century of Saints", but the age of the most wondrous of Saints.

Read more here. And about her relationship with the Holy Souls.

(From Catholic Tradition)