During the second term of her final year at Drama Centre London, Kari won the role of Lucy in The Inbetweeners Movie. She has since had various roles in a number of plays. She also appeared in the fourth series of the BBC Three supernatural drama series Being Human and the second series of Silk. She formerly appeared in the BBC Three sitcom Cuckoo, which premiered on 25 September 2012, as well as in The Musketeers, in which she portrayed Constance Bonacieux. In 2013, she played Danielle in the ITV comedy The Job Lot. In 2014, she reprised the role of Lucy in The Inbetweeners 2.