A family member of the television personality tells us ... Lizzy passed away Thursday at her home in North Carolina after struggling with breast cancer for several years.

Her father, Pat, broke the news on Facebook last night, moments after his daughter passed away ... and thanked her fans for supporting her and the family.

Musi rose to prominence back in 2018 when the hit spinoff of 'Street Outlaws' following drag racers came out ... and, she appeared alongside her dad who himself is an 8-time PDRA Pro Street World Champion.

Lizzy quickly made an impression on the other drivers ... becoming the first woman to win a 'No Prep Kings' event during the show's second season.

Lizzy first shared her breast cancer diagnosis last year ... telling fans, at the time, the cancer had already metastasized to her lymph nodes and liver. She kept fans updated regularly on her condition as she went through treatment, sharing pics of her bald head.

Months after her diagnosis, she started dating Jeffrey Earnhardt -- NASCAR legend Dale Earnhardt Sr.'s grandson and Dale Jr.'s nephew. The couple posed in photos just weeks before her passing.

Lizzy was just 33.