In 2001, she won the all-around title, gold on bars and beam and bronze on floor at the Romanian junior championships in her age category.

At the European Championships, Volos Greece she medaled silver with the team and she finished sixth on the uneven bars finals.

[9] She ended 2006 by pairing with Marian Drăgulescu for the silver medal at the Swiss Cup and by winning gold on beam and bronze on floor at the Glasgow Grand Prix.

In the qualification round of the 2007 European Championships, Amsterdam, The Netherlands she placed second all around, third on beam and floor and fourth on bars.

[12] At the 2007 World Championships, she helped her team to qualify in the third place by scoring the highest all around mark of the women's qualifications.

She won the Swiss Cup mixed pair event with Flavius Koczi, medaled gold on bars and bronze on floor at the Glasgow Gand Prix and won gold on beam and floor and bronze on bars at the Ghent World Cup[10] In 2008, she competed at the European Championships in Clermond-Ferrand, France.

[16] Had there been a senior all around competition, Steliana would have won the title with her 60.700, highlighted by a 15.400 on bars (toe-on-1 and 1/2 to Jaeger; toe-on-Tkatchev-Pak) and 15.800 on beam (flip-flop full).

[17] A picture of her performing on the floor exercise at these European Championships appeared on the cover of May 2008 International Gymnastics Magazine.

The process, Nistor told Prosport, was "draining," and she only competed bars at a dual meet with Italy the following week to give her mind and body a rest.

After retirement from gymnastics she studied physical education, sports, and coaching in her hometown of Sibiu and was a representative of sportswear products.

[22] Nistor skills included a handspring to back full on balance beam, as well as a front flip to Arabesque.