Legall has worked in a variety of social care roles, including as a nurse and a social worker.[12]
She was a member of Black Alliance, an Anti-Apartheid group based in Cardiff that was founded in 1969. She recalled a protest the Black Alliance held in 1969, in Cardiff, where police arrested all the black men. The mounted police then began herding people down side-streets and Legall was only able to avoid arrest when a woman in a nearby house gave them refuge. Legall went on to organise with Hanef Bhamjee, and was a founding member of Wales Anti-apartheid Movement (WAAM) in 1981.[4][13][14]
In 1987 Legall was involved in the four part film series, Struggles for Black Communities. Made by Colin Prescod, the films were commissioned by the Institute of Race Relations and aired on Channel 4.[5][7]
In 1988, she founded AWETU, which means "our unity" is Swahili. It was the first black led mental health charity in Wales and remained the only mental health group that supported minority ethnic people in Wales until its merger with the Cardiff & Vale Coalition of Disabled People in 2011. The two groups then become Diverse Cymru.[15][16] AWETU provided an advocacy and befriending services, drop in groups, and training services for authorities to help them understand the specific mental health struggles minority ethnic groups may face.[17]
She established FullEmploy Wales in 1989.[18][19] The organisation was a Welsh specific sister organisation to FullEmploy, which aimed to place black and minority ethnic young adults into suitable job roles.[20][21] The organisation later renamed to become Newemploy, before closing in 2001.[21][19]
In 1995, she helped found BAWSO, a charity focused on supporting black and minority ethnic domestic abuse survivors in Wales.[18][15] The charity runs refuges, offers support in the community, and a 24-hour helpline.[22]
In July 2020 the First Minister of Wales, Mark Drakeford formed a group to audit street names, building names, and public monuments that were linked to the British slave trade. This came after a month of Black Lives Matter protests.[23][24] Legall was appointed as the chair of the group.[25]
The group's findings were published in November 2020, in The Slave Trade and The British Empire Report.[25] The audit found that over 200 buildings, monuments, and street names across Wales were named in commemoration of people directly linked to the slave trade.[26] These commemorations rarely addressed any connections to slavery.[27] The findings also highlighted the lack of commemorations for black and Asian people within Wales.[26] To potentially address this, the report identified 41 historically significant Welsh black people who could be commemorated in the future.[25]
Following the report, Legall explained that the group intentionally choose not to make recommendations around the commemorations, instead believing that decisions around them should be made by the people to who live near them.[27][3] Commenting on what she wanted to see, Legall hoped that the audit would help educate younger generations on where Welsh wealth came from, and hoped to see more commemorations for people of colour.[27]
In October 2020 Legall spoke about her experience growing up as a black woman in Wales, in the BBC documentary Black and Welsh by Liana Stewart.[28][2]
She was involved in the Picture Post: A Twentieth Century Icon, an 2025 National Museum Cardiff exhibition that focused on photography from the 1930s to the 1950s. Legall helped select photographs that represented Tiger Bay.[10][29]
Legall sits on the committee boards of a variety of organisations including The Heritage & Cultural Exchange, a Cardiff based community organisation that archives the history of Tiger Bay.[30][31] She is also an honorary vice chair of LLafur, an organisation formed in 1970 to promote the people's history of Wales.[31][32] Previously Legall served as a director of Butetown History and Arts Centre, which announced it's planned closure in 2016.[15][33] She is a board member of Diverse Excellence Cymru[15][34] and a non-executive member of Cadw's board.[31]
Legall was a member of the Cardiff Bay Rugby Codebreakers committee, which campaigned and fundraised to create a statue celebrating sportsmen from Cardiff Bay. The committee erected the Codebreakers Statue in Cardiff Bay in July 2023.[35][36] It was the first statue within Wales that featured non-fictionalised, and named black men.[37]