Mihalic trained as a police officer and studied at the Fachhochschule für öffentliche Verwaltung Nordrhein-Westfalen (University of Applied Sciences for Public Administration North Rhine-Westphalia), graduating as a Diplom-Verwaltungswirt (FH).

At the end of the 2000s, she acted, together with her colleague Dennis Melerski, in the German reality TV series Achtung Kontrolle!

In the 2013 federal elections, Mihalic ran in the Gelsenkirchen constituency and in 7th place on the North Rhine-Westphalia state list of Alliance 90/The Greens.

In addition to her committee assignments, she has been serving as deputy chairwoman of the Parliamentary Friendship Group for Relations with the Northern Adriatic States.

[13] In the negotiations to form a coalition government under the leadership of Minister-President of North Rhine-Westphalia Hendrik Wüst following the 2022 state elections, Mihalic was part of her party’s delegation.

[14] As a domestic policy spokeswoman and police officer, Mihalic's parliamentary mandate focuses on right-wing extremism[15] (e.g. "Reichsbürger"[16]), Islamism,[17] weapons law,[18] the establishment of security authorities in Germany and Europe,[19] civil defense and emergency management[20] and civil service law.