She was active in the Labour Party, involved in several peace movements, notably at Greenham Common in 1981 and organised community support during the 1984 - 1985 miner's strike.
[2] She walked the approximately 100 miles from Cardiff to Newbury in August 1981 to draw attention to the proposed installation of nuclear weapons at RAF Greenham Common.
Her activity as a member of the Women for Life on Earth group led to others joining its protest.
[1] During the coalminer's strike in 1984 - 1985 she had a key role in South Wales for fund-raising and distribution of food while based at the Miners Welfare Hall in Ystradgynlais that provided support for all those in the Upper Swansea Valley.
[1] In 2020 a Purple Plaque was installed at the Miners Welfare Hall, Ystradgynlais to mark Stallard's life and activity as a peace campaigner.