Brabham and Betty had three sons together: Geoff, Gary, and David. All three became involved in motorsport, with support from Brabham in their early years. Between them, they have won sportscar and single-seater races and championships. Geoff was an Indycar and sportscar racer who won five North American sportscar championships as well as the 24 Hours of Le Mans, while David competed in Formula One for the Brabham team and has also won the Le Mans race as well as three Japanese and North American sportscar titles. Gary also drove briefly in Formula One, although his F1 career consisted of two DNPQ's for the Life team. Brabham and Betty divorced in 1994 after 43 years. Brabham married his second wife, Margaret in 1995 and they lived on the Gold Coast, Queensland. Brabham's grandson Matthew (son of Geoff) graduated from karts in 2010 and won two ladders of the Mazda Road to Indy, eventually racing in the 2016 Indianapolis 500 and winning two Stadium Super Trucks championships. Another grandson, Sam, the son of David and Lisa , whose brother Mike also was an F1 driver, stepped up to car racing from karts in 2013 when he made his debut in the British Formula Ford Championship. The Brabham family have been involved in world-class motorsport for over 60 years.