Sister Mary Winifred was born and raised in Houston, Texas. For many years a Life Professed member of the Community of the Holy Spirit in New York, she later lived in the Community of the Ascension and as a solitary Religious at Ascension Hermitage and Sanctuary in Upper Fairmount, Maryland, in the Episcopal Diocese of Easton.
She is no longer a Religious Sister and has now resumed using her legal birth name, Emily Shepherd, but retains Sister Mary Winifred as a pen name. She has been a member of the Vergers Guild of the Episcopal Church since 2006, and is a Fellow of the Guild.
She is the author of numerous articles and other works.