Khanjin ran as the Progressive Conservative Party of Ontario candidate in the 2018 Ontario general election for the riding of Barrie-Innisfil, won with 22,121 votes, and defeated the Liberal incumbent by 16,576 votes.

Following her election in 2018, during Khanjin's first term, she served as a member of Finance and Economic Affairs, Estimates, and Government Agencies Committees.

On June 5, 2019, she introduced an Act to proclaim the Provincial Day of Action on Litter as her private member's bill;[7] on March 1, 2020, Khanjin and Cuzzetto introduced an Act to proclaim Sickle Cell Disease Awareness Day and Thalassemia Awareness Day,[8] and; she co-sponsored an Act to proclaim the month of August as Emancipation Month on December 8, 2021.

To raise awareness of the importance to a clean environment of not littering, Khanjin introduced an Act to proclaim the Provincial Day of Action on Litter every second Tuesday in May in each year as her first private member's bill.

This bill proclaims that June 19 as Sickle Cell Disease Awareness Day and May 8 as Thalassemia Awareness Day in Ontario would increase awareness of these blood disorders in our province and dedicate a day to support individuals who have sickle cell disease or thalassemia and their families.