She was appointed to the Executive Council of Quebec on December 18, 2008, as Minister of Justice and Attorney General.

[4] Following the 2014 provincial election the Liberals returned to power, and she was appointed Minister of Immigration, Diversity and Inclusiveness.

On 11 October 2017, Weil was sworn in as the first Ministre responsable des Relations avec les Québécois de langue anglaise.

The Liberals lost the election and returned as the official opposition to a new CAQ government.

On June 6, 2022, Weil announced she would not be seeking re-election in the 2022 election and bowing out of politics after 14 years.