The actress reminisced about her time on the set of the 2015 movie, which was largely shot in Namibia, in an Instagram post on Thursday (May 14), when she shared a rare snap of herself with her eldest child, Jackson.
The image features Charlize, dressed as her war captain character Imperator Furiosa, seated in the front of a car, cuddling the tot against her chest.
"I became a mom right before we started shooting," she captioned the sweet photo, which featured a purple heart emoji over the face of her now-seven-year-old kid.
"At least my child will forever have the fun fact of 'I spent most of the first year of my life in a war rig...'"
Charlize adopted Jackson, who was born a boy, in March, 2012, but last year (19), revealed she had been raising him as a girl at her little one's request.
"I thought she was a boy, too, until she looked at me when she was three years old and said: 'I am not a boy!' So there you go!" the star told the Daily Mail.
Charlize, who is also mother to a daughter named August, added, "My job as a parent is to celebrate them and to love them and to make sure that they have everything they need in order to be what they want to be. And I will do everything in my power for my kids to have that right and to be protected within that."