Dale Earnhardt, Jr., is mourning the death of his mother, Brenda Jackson. JR Motorsports announced on Monday (April 22) that Jackson had died at the age of 65 after battling cancer.

"I'm glad her suffering has ended and she can be at peace," the NASCAR champion tweeted. "She would be in tears of happiness over the words of support and remembrance she's been shown today. Our family appreciates it as well. She will live in our hearts forever."

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Jackson worked for JR Motorsports, which Earnhardt Jr., his sister Kelley Earnhardt Miller and Rick Hendrick own, since 2004. The company remembered her fondly in an online post.

"Known for her wit, charisma and unparalleled ability to cut to the heart of any matter, Jackson became an instant favorite to her friends and colleagues at JR Motorsports when she joined the company," the post reads. "Her sarcastic musings and straightforward approach injected a brand of humor at JR Motorsports that became part of its fabric as it grew into a full-time NASCAR racing operation in 2006 and a championship-winning organization in 2014."

Jackson's father was the legendary NASCAR fabricator Robert Gee, who built winning cars for many drivers. He built a car for a then up-and-coming race car driver named Dale Earnhardt, and Jackson and Earnhardt married in 1972. They had two kids — Kelley and Dale Jr. — before divorcing, and Jackson retained custody of their kids after they separated. She married Willie Jackson in 1985, and the couple were married for 33 years, right up until her death.

According to JR Motorsports, Jackson was an avid gardener who also enjoyed fashion, cooking and home decorating. She's described as being very devoted to her children and grandchildren, as well as a staunch supporter of the Dale Jr. Foundation and other charities.

Funeral plans for Jackson have not been announced.

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