She urged her daughter to "stay in there" until she found the tampons.
Isabella eventually found the item in questions, writing: "OH WAIT. They're here tucked away in a corner unlabelled."
Her mother replied sarcastically: "No big sign reading 'SUPER PERIOD CENTER?'"
"They labelled the tiny shelf of joint braces," Isabella wrote. "But not the massive aisle of stuff for your vagina?"
Belinda deadpanned: "Because there is NEVER a sign for that section. Vaginas are SECRET."
Her daughter took the joke one step further, writing: "VAGINAS ARE MYTHS, WHISPERED QUIETLY IN SECRET AMONG ONLY THE BRAVEST OF MEN, COURAGEOUS ENOUGH TO EVEN MENTION THE NAME."
She continued: "BUT SERIOUSLY WHY ARE MEN SO AFRAID OF WOMEN AND VAGINAS?? DO THEY THINK IF THEY ACKNOWLEDGE THEIR EXISTENCE WE WILL SHOOT OUR LASER ESTROGEN BEAMS OUT OF OUR EYES AT THEM AND DISINTEGRATE THEM WITH EASE."
After Belinda encouraged her to continue to "smash the patriarchy", the teen even drew her out a humorous "map" of the supermarket layout - with "the vagina zone" cordoned off and "danger: do not enter" signs.
Since Belinda proudly posted the exchange on Facebook, it has been liked and shared by more than 100,000 people.
She said that while she never expected it to go viral, she was pleased that most people appeared to find it as "funny and innocent and hilarious" as she did.
However, some had been laying into her "like a pack of wild dogs", openly criticising her parenting abilities.
"I can't even count the parenting mistakes I've been accused of," she wrote.
"Or the excessive mansplaining about how easy it is to find feminine hygiene products or how you could always just ask someone or just BE PREPARED, etc. etc.
"Oh, men of the Internet, is there anything you don't know better than us, even about menstruation? Clearly not."