She became active in Sinn Féin in the 1960s, and when the organisation split in 1970 she remained with Official Sinn Féin which subsequently became the Workers' Party. She has contested several elections on behalf of the party. In March 1992, Donnelly was elected as President of the Workers' Party
following the breakaway of a parliamentary grouping from the party. She retired from the position in 1996, but remains an active member of the Workers' Party. She was a candidate for the Workers' Party in the
1992 Irish general election, contesting the
Dublin North-East constituency. She received 239 votes (0.60%), and was eliminated on the third count. That years election demonstrated the level of support
Democratic Left had taken in its split from the party nationwide, with
Pat McCartan outperforming Donnelly by over 3,000 votes. She and James McLaughlin were both selected as Workers' Party candidates to run in the
East Londonderry constituency for the
1996 Northern Ireland Forum election. Both received 75 votes (0.2%) in total. In 1997, she was the Workers' Party candidate for
that years Westminster election, receiving 238 votes (0.47%). In December 2018, she delivered the
eulogy at the funeral of former leader of the Workers' Party, and veteran
Official IRA member,
Seán Garland. == Personal life ==