Rainville was born in New London, Connecticut. After graduating from the Chamberlain-Hunt Academy (1975), Rainville received a Bachelor of Arts in Education from the University of Mississippi (1979).
Following graduation, she entered the United States Air Force, and was a 1979 Distinguished Graduate of the United States Air Force Officer Basic Military Training Program at Lackland Air Force Base, Texas. She served on active duty from 1978–1984, then transferred to the 174th Consolidated Aircraft Maintenance Squadron, New York Air National Guard, Syracuse, N.Y. She also served in the Air Force Reserve in Minneapolis, Minn. and the Vermont Air National Guard before becoming the Adjutant General of the State of Vermont in March 1997. The position of Adjutant General carried with it the rank of Major General. The first woman in the history of the National Guard to hold this position, Rainville commanded 3,800 members of the Vermont Army and Air National Guard. She also served as the commissioner of the Military Department, State of Vermont. As Adjutant General, Rainville ensured that the Army and Air National Guard worked as a joint force enabling the Air and the Army Guard to rapidly response to natural disasters in the state.
Along with her work in Vermont, Rainville served on the Reserve Forces Policy Board, the executive committee of the Adjutant Generals Association of the United States, and was elected vice chair of the Board for Air National Guard of the National Guard Association of the United States.
In 2005, Rainville began consulting with members of the Republican and Democratic parties regarding a possible run for the U.S. House of Representatives or the U.S. Senate. She was courted by members of both parties. Rainville announced her candidacy in the early spring of 2006 as a Republican, stressing government reform, ethics, homeland security, and a strong national defense.
In 2006, Rainville ran for Vermont's at-large congressional district. Early in the campaign, Rainville signed a Clean Campaign Pledge in which she vowed to not attack her opponent Welch, and condemned negative TV ads by third parties in the race. Rainville’s campaign, though a positive one, made some gaffes. A plagiarizing scandal (originally documented by Julie Waters, a Vermont blogger) involving one of her staffers resulted in a drop in the polls.
A strong national anti-Republican wave, based partially on dwindling support for the post-invasion Iraqi occupation, combined with a desire to restore an oversight role to the Congress, made winning the seat an uphill battle. On Election Day, Welch was elected with a 9 percent lead. It was Rainville’s first run for office.
In 2007, Rainville was appointed counselor to the Department of Homeland Security's Federal Emergency Management Agency (FEMA) administrator and deputy administrator for Continuity Programs. Rainville served as the assistant administrator from 2007–2009 and was responsible for ensuring that FEMA performed its role as Lead Agent for Federal Executive Branch Continuity Programs, including preparation and implementation of Continuity of Operations, Continuity of Government and Contingency Programs across a full threat spectrum. Additionally, she oversaw implementation of continuity taskings assigned to FEMA/DHS in HSPD-20/NSPD-51 including developing and promulgating Federal Continuity Directives, conducting biennial assessments of all Federal Executive Department and Agency continuity capabilities and developing continuity guidance for state, local, territorial and tribal governments and the private sector.
Rainville is the daughter of the late Nick and Lucille Trim of Port Gibson, Mississippi. Lucille Trim was murdered in a robbery by then 19 year old Otis Byrd. Byrd was convicted of capital murder in 1980 and was sentenced to life in prison. Byrd was paroled in 2006. Byrd was founding hanging from a tree in 2015 and the death was ruled a suicide. Rainville resides in Virginia and has three children. She was divorced from her husband Norman Rainville in 2003, and in 2009 she married Paul McHale, a former Congressman from Pennsylvania and former Assistant Secretary of Defense. McHale is a member of the Democratic Party.