Childers originally joined the Labour Party before the 2004 local elections, but when she failed to get a nomination to run for Dún LaoghaireRathdown County Council, she switched to the Green Party and was elected to represent it as a Councillor.[6]
In November 2011, she refused to support the Irish Government's nominee to the European Court of Auditors, Kevin Cardiff.[10] who was head of the Financial Services Division of the Department of Finance.[11] Childers said she had concerns about his suitability given the uncertainty around his role in the Irish Bank Guarantee and a recent serious error in the calculation of the Irish public finances.[12]
Childers campaigned unsuccessfully to have former Fianna Fáil TD, Minister and European Commissioner Pádraig Flynn, stripped of his Commission pension after the Mahon Tribunal, which found him to have received corrupt payments. The reason the Commission gave was that the findings "do not represent the verdict of a court after due process".[13]
She resigned from the Parliamentary Labour Party on 5 April 2013, saying "..I no longer want to support a Government that is actually hurting people".[14] She resigned from the Labour Party itself in July 2013.[15] She was a non-attached MEP from 2013 to 2014.
In June 2013, she called upon Minister Phil Hogan to convene a commission to decide on new constituency boundaries. She noted a reduction in European Parliamentary seats allocated to Irish constituencies, which had fallen from 12 to 11 as a consequence of the accession of Croatia to the European Union.[16] She further called for a ban on the placement of election posters on local council-owned poles, but not on the more common eircom poles or Electric Ireland poles. The commission was appointed in July 2013.[17]
In January 2014, Childers announced that she would switch from the East constituency to the Dublin constituency at the 2014 European Parliament election.[18] For the 2014 election the East constituency was abolished with the northern part transferred to the new Midlands–North-West constituency, and the southern part transferred to the South constituency.