In 1996, Sârbu joined the PSD (known as PDSR at the time), and in 2001 became an Adviser for the Controlling Body of the Romanian Premiership in the Năstase cabinet. She withdrew from this office in 2003, and became a State Secretary in the Ministry of Education and Research, later serving as Head of the National Authority for the Youth. In her party, she became one of the leaders of the youth and women's wings, taking part in the International Union of Socialist Youth structures, and attending its Congress of 2004.
She is the wife of the incumbent Prime Minister of Romania, Victor Ponta. They have a daughter.