Mary began meditation in the Vipassana tradition while living in Tennessee in 1993. Since then, she has attended over 25 silent meditation retreats of seven to ten days each. She has a daily practice that includes yoga, Vipassana, metta, and jhana meditation. Her teachers have included Rodney Smith, Leigh Brasington, Gregory Kramer, Lucinda Greene, Tara Brach, Hugh Byrne, and Jonathan Foust. Since 2009, May has served on the board of Directors of the Southern Dharma Retreat Center, located near Asheville, North Carolina.
Currently, Mary teaches Vipassana meditation classes on behalf of IMCW at St. Mark's Church on Capitol Hill on Monday evenings, at All Soul's Church in Columbia Heights on Sunday evenings, and at East Meets West Yoga Studio in Vienna on Sunday mornings. She also sometimes substitute teaches the Sunday morning meditation classes at Lil Om Yoga Studio in Tenleytown. Mary participates in two sutta study groups in the D.C. area.
In September 2012, Mary graduated from the Community Dharma Leadership IV program sponsored by Spirit Rock Meditation Center. She is a full teacher at IMCW.