Her breakthrough roles were as Nina Löwander in Vår tid är nu (2017–2021) and as Alice in Unga Sophie Bell (2015).

A maternal ancestor, Erik Gustaf Gejier was a renowned Swedish writer, historian, poet, philosopher and composer.

[citation needed] Since 2017, she has been cast in the role of Nina Löwander in the drama series Vår tid är nu (English title: The Restaurant), broadcast on SVT.

[6] In 2020, Stiernstedt was awarded the honorary prize for being the best dressed woman in Sweden at Swedish Elle Magazine's Fashion Gala.

[8] Stiernstedt revealed that she had planned to marry in the summer of 2020, but due to the COVID-19 pandemic, the wedding was postponed.