Funding issues caused Freiberg to drop out of Skip Barber after four wins in 2011, but she later drove for JDC MotorSports in the 2012 Star Mazda Championship, finishing ninth in the points standings.
She debuted in the IMSA SportsCar Championship in 2016, running a partial schedule in the Prototype Challenge and Grand Touring Daytona (GTD) categories.
Her best finish was second in GTD at the 12 Hours of Sebring, taking class and outright podiums for DAC Motorsports in the 2017 Lamborghini Super Trofeo North America Championship.
In December 2004, Freiberg made her national debut in a World Karting Association (WKA) event at Daytona International Speedway's road course.
[5] In her first season, Freiberg finished fourth overall in the regional Championship Enduro Series (CES) and seventh overall in the national WKA points standings in 2005.
[1][12] Soon after, she also joined Lyn St. James's Women in the Winner's Circle Driver Development Academy in Phoenix, Arizona,[11][9] setting for herself the goal of reaching the IndyCar Series.
[7][17] As a result, she visited race tracks and spoke to team owners who declared an interest in her through various channels because she was unable to employ a publicist.
[12][15] Towards the end of 2011, Freiberg was contacted by an official from TrueStar's driver development program Women Empowered Initiative, which had watched her compete in the Skip Barber championship season.
[7][17] Although she desired another season in the Star Mazda Championship before switching to Indy Lights,[12] Freiberg researched the possibility of driving sports cars,[7] and competed for EFFORT Racing in the 2013 GT3 Cup Challenge.
[4] At the season-opening round at Sebring, she twice finished in the overall top-five,[20] and took second place outright in the first Laguna Seca race, tying Madison Snow for the championship lead.
48 Fall-Line Motorsports BMW M3 Grand Sport (GS) car with Shelby Blackstock as she struggled to find sponsorship for a full-time seat.
96 BMW M3 Grand Touring Daytona (GTD) car in the 2016 IMSA SportsCar Championship North American Endurance Cup, and shared the No.
[29] She debuted at the season-opening 24 Hours of Daytona alongside Jens Klingmann, Bret Curtis and Marco Wittmann, finishing 22nd in the GTD class and 48th overall after multiple technical problems.
[36] After spending months locating sponsors to fund her career,[7] Freiberg signed for DAC Motorsports to drive select races of the 2017 Lamborghini Super Trofeo North America Championship after she was contacted by the team in May that year.
[38] In the opening round of the 2018 Continental Tire SportsCar Challenge, the BMW Endurance at Daytona, she and Audi Sport TT Cup driver Gosia Rdest formed the first all-female team in the GS class.
[41] In December 2018, Freiberg shared a Shift Up Now-entered BMW E30 with Lynn Kehoe, Kristina Esposito, Mandy McGee, and Karen Salvaggio in an all-female team at the 2018 25 Hours of Thunderhill, finishing second in class and 25th overall.