She received her Juris Doctorate from Duquesne University in 2011. While in Law School, MacKenzie worked for a local law firm as a certified legal intern. Early in her education, she was involved with several law journals and served as the Article Editor for the Business Law Journal, and was the Executive Managing Editor of the Criminal Law Journal. Additionally, MacKenzie received the Outstanding Oral Argument Award for her work in a Mock Appellate Argument.
Mackenzie has been practicing law since being admitted to the Pennsylvania bar in 2011. In 2013, she was admitted to practice federal law in the United States District Court for the Western District of Pennsylvania.