June Darby is Jack's mother and is one of the only adult civilian humans to know of the autobots. She was initially unaware of the Autobots' existence for long until she was targeted by MECH and Airachnid. She was saved by Jack and Arcee and told the whole truth, after which Jack and Arcee took her to the Autobot Base to meet the rest of Team Prime.
June also revealed to Arcee that Jack's dad left them and that is why she's overprotective.
June returns in Crisscross where she catches Jack breaking his curfew and failing to do his job at the burger shop. June thinks that Jack has been street racing with his motorcycle and grounds him for that, with no use of the motorcycle. June kisses Jack on the forehead and tells him she loves him. The next day, June calls Jack and tells him that she's coming home early to make dinner for Jack.