[2][5] Sillitti began her political career working in the office of Nassau County Legislator Dave Mejias.

[4] She later worked as director of legislator affairs and deputy chief of staff for Town Supervisor Jon Kaiman.

[4] Sillitti was nominated at the Nassau County Democratic Committee Convention on February 11, 2020, after Assemblyman Anthony D'Urso announced he would be retiring.

[4] Sillitti ran on a platform to increase state funding for local schools and roads, reducing property taxes, and protecting Long Island Sound and drinking water.

[3] In late February 2021, after the Andrew Cuomo sexual harassment allegations became public, Sillitti was among a group of assemblywomen who issued a statement calling for an independent investigator to be appointed by Attorney General Letitia James.