On April 16, Earnhardt met up with Jackson's brothers, Robert and Jimmy Gee.
"My last name's Earnhardt but its clear I took a lot from my mom's side of the family," Earnhardt wrote. "I got to see my two Uncles Robert and Jimmy Gee today. Both heroes of mine."
After news broke of his mother's death, the comments section on the post became a place where fans left their condolences.
"My deepest sympathies to you & your family over the loss of your Mom. God’s peace surround you," one wrote.
"May the Lord bless and comfort you Dale, the entire Earnhardt and Gee families in this difficult time with the loss of your sweet mama. My thoughts and prayers are with you and yours," another wrote.
On Monday, JR Motorsports announced that Jackson lost her battle with cancer. She was 65. She is survived by her husband, William Jackson, Earnhardt and her sister Kelley Earnhardt Miller, step-daughter Meredith Davis, six grandchildren, her brothers and dog Scully.
Jackson's father was legendary NASCAR fabricator Robert Gee, who built several cars, including one for Dale Earnhardt Sr. She was married to Earnhardt Sr. from 1972 until 1974. Earnhardt and Kelley stayed with their mother.
"I’m glad her suffering has ended and she can be at peace," Earnhardt wrote on Twitter Monday. "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."
"My mom, my biggest advocate and my friend...at peace that she’s at peace," Kelley added. "No more suffering & no more pain...made new in the arms of Jesus, reunited w/ones she loves & as a believer I’ll be reunited w/ her one day. Thank you to all that are offering your prayers, hugs & support."
Back in 2017, Earnhardt and his mother appeared on ESPN together to mark Mother's Day. In the segment, he read a letter he wrote to her, not knowing she was right behind him.
“I think back as a 6-year-old kid, you a single mother, us losing everything in a house fire. You gave custody of us two kids to our father, knowing he could provide us with a promising future," Earnhardt wrote. “I’m thankful that we are together today, as I am now older and wiser to appreciate the sacrifices that you made for us. You never failed at making me feel loved. I love you. Happy Mother’s Day, Mom.”
Photo credit: Instagram/Dale Earnhardt Jr.