Taylor Myers, from the US, posted a selfie of herself with tears in her eyes while her daughter, Sophie, was sat behind her in the car.
She said they were in the queue at the supermarket to pay for a food shop when her daughter started “whining over a big of crisps” she had taken away.
“She’s relentless. I know this. I live with it,” the mum wrote on Facebook on 27 July.
“Her ADHD and obsessive little heart gets on these subjects of things she finds unjust and wrong and it doesn’t stop until she eventually falls asleep or something very dramatic happens to snatch the attention away.”
Myers stood in line ignoring her daughter, refusing to give in to her.
But then she heard a woman in the line shout: “Oh, for Christ’s sake, give her a cookie so she’ll shut up.”
Myers continued, on the Facebook post: “I could’ve responded in a nicer way. I could’ve explained to her that my four-year-old has pretty severe ADHD, I raise both my children alone, I’m doing my best, and had no choice but to wait it out for the groceries.
“Instead, I heard, ’She’s four years old and you need to mind your own f***ing business’ come out of my mouth.”
The mum went to the self-checkout so she could avoid facing anyone else commenting on her parenting skills. She had tears rolling down her face.
“[At this point] I’ve lost it,” she wrote. “I’m angry, my feelings are hurt, I’m offended, and I’m just freakin’ sad that I can’t have one good experience in a store with my children.
“As I scan my things, a woman walks up and begins to talk to Sophie. She asks her questions to distract her, and backs me up when Sophie begins to go on about wanting the crisps.
“Honestly, this woman could’ve been the antichrist and I would’ve had more appreciation for her kindness and compassion than I have for anyone else I’ve ever encountered.
“It only takes one comment to break someone down. You never know what someone’s going through. Mamas have to stick together.”
“Don’t let it get you down,” one mother wrote. “It happened to me. Last year I went off on a bitch. You’re a great mum and it’s ok she’s like that.”
Another wrote: “Oh I’ve been there. Don’t let her get you down. You are doing an amazing job - us mums need to stick together.”