After appearing with Eric Bischoff's now-defunct Mat Rats promotion as a ring announcer, Nattie Neidhart trained under her uncles in the Calgary, Alberta based Hart Dungeon. She debuted in 2000 in Stampede Wrestling, the promotion owned by her uncles Ross and Bruce, and in 2003 she began a feud with Belle Lovitz that lasted until 2005 when the former enemies joined forces against the Myers Family.
In the summer of 2004 Neidhart toured England, and in March 2005, she embarked on a two month wrestling tour of Japan, intending to hone her skills. While in Japan she was billed as Nadia Hart. She returned to Canada on May 6, and promptly turned heel, announcing that "Nasty Nattie" had been born. On June 18, 2005 Neidhart debuted in the Edmonton, Alberta based Prairie Wrestling Alliance promotion, renewing her feud with Belle Lovitz.
Neidhart defeated Anna Marie, Belle Lovitz and Ma Myers in a four way match to become the first Stampede Wrestling Pacific Women's Champion on June 17, 2005. She later vacated the title.
In addition to her professional wrestling career, Neidhart has received training in amateur wrestling and mixed martial arts. On October 8, 2006 Neidhart won the ECCW Supergirls Title from Ivory on a Big Time Wrestling show in Newark, California. On October 27, 2006 she lost the Supergirls Title in Surrey, British Columbia to Nikki Matthews in a three-way match that also involved Veronika Vice.
On January 4, 2007, Neidhart signed with World Wrestling Entertainment. She made her Deep South Wrestling debut on February 15, 2007 assisting in the intermission raffle. She made her wrestling debut on March 8, 2007 losing to Krissy Vaine. Then on March 15, 2007 she teamed up with Shantelle Taylor to defeat Angel Williams and Krissy Vaine.