She took a few years break from acting to attend a university. In 2009, she played the lead role of Megs in short film The City of Lights. In September 2010, she appeared in three episodes of the CW hit teen drama series 90210, a spin-off of the 1990s Fox series Beverly Hills, 90210. In February 2012, McKenna landed a role in the TNT revival of the CBS prime-time soap opera, Dallas. She also made guest appearances in Two and a Half Men, Sketchy and Guys with Kids. In March 2014, she appeared in the horror film Haunted along with Luke Kleintank and Lesley-Anne Down.