By 2011, she had completed her legal preparatory service (referendariat) in the district of the Erfurt Regional Court [de], passing the second state law examination.

In the 2009 Thuringian state election, she stood for the first time as a direct candidate for the CDU in the Sonneberg I constituency and won with 43.2 percent of the first votes against Michael Gerstenberger [de] of the Left Party.

In the 2019 Thuringian state election, she again won the direct mandate in her constituency with 41.5 percent, clearly ahead of the candidate from the Left Party.

Meißner was also the spokesperson for the CDU parliamentary group on the issues of family, senior citizens, and the disabled, as well as responsible for the area of ​​equal opportunities.

On 13 December 2024, Meißner was appointed Thuringian Minister for Justice, Migration and Consumer Protection [de] in the Voigt cabinet.