Marsha is a variant of Marcia — from the Latin Mars, the Roman god of war. Marsha P. Johnson (1945-1992) — Black American transgender activist and self-identified drag queen; a prominent figure in the Stonewall uprising of June 1969 in Greenwich Village, widely credited as a key catalyst of the modern LGBTQ rights movement. Co-founded the Street Transvestite Action Revolutionaries (STAR) in 1970 with Sylvia Rivera to house homeless transgender youth. Her body was found in the Hudson River on July 6, 1992; initially ruled suicide, the case was reopened in 2012 as possible homicide. Time named her one of the 100 Most Influential People of All Time (2020).
Subject of The Death and Life of Marsha P. Johnson (2017 Netflix documentary).
In Pythagorean numerology the letters of Marsha reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.