A photo posted by a parent to social media has highlighted the stark reality of growing up in America’s climate of gun violence.

Stacey Wehrman Feeley of Traverse City, Michigan, posted a photo of her daughter standing on top of the toilet seat to her Facebook page in mid-June.

In the post accompanying the image, she wrote that when she took the photo, she thought her daughter was being a “mischievous little three-year-old”.

She “broke down” when she found out that the little girl was in fact practising what she’d been taught at preschool: how to hide in a bathroom stall from a gunman.

“At that moment all innocence ... I thought my three-year-old possessed was gone,” wrote Feeley.

Her post went on to call for US politicians to address gun violence – and to ask what she and others could do to help.

“Politicians – take a look. This is your child, your children, your grandchildren, your great-grandchildren, and future generations to come,” she wrote. “They will live their lives and grow up in this world based on your decisions. They are barely three and they will hide in bathroom stalls standing on top of toilet seats.

“I do not know, what will be harder for them? Trying to remain quiet for an extended amount of time, or trying to keep their balance without letting a foot slip below the stall door?”

Wehrman Feeley questioned the potential of politics alone to end gun violence in America, and called for cross-sector and community collaboration.

“Entrepreneurs, innovators, are you there? Can I help? Can I help you make a difference? I want to offer support. I cannot give you techie advice, expertise in healthcare, or financial backing, BUT maybe I can point you in the right direction? Maybe I know someone who knows someone who can help?

“Incubators, investors… if this issue concerns you, do what you do best and help make change. Can I help? ... . Hollywood, the PSA’s are good, but not good enough. Eventually they disappear and are forgotten.”

She concluded with an entreaty to spread the message: “I am not pretending to have all the answers or even a shred of them, but unless you want your children standing on top of a toilet, we need to do something!”

Her post had been shared close to 37,000 times in a week since it was published.

“The world’s going crazy ... a three-year-old child who has had to learn and understand that standing on the toilet may be necessary to save her life,” marvelled one of the more than 5,000 comments.

Another suggested that posting the picture could have a counterproductive effect: “Should a potential shooter see this, they now know how the kids are being taught to hide from them. I know it’s far fetched, but you never know. Just saying. It HAS gone viral.”

Wehrman Feeley had hashtagged her post #prayfororlando, a reference to the gun massacre at the Pulse nightclub in Orlando, Florida, on Saturday 11 June. Nearly 50 people were killed, and several more than that were injured, in the worst mass shooting of its kind in US history.

After the attack, several survivors recounted their terrifying experience of hiding in the club’s bathroom, standing on the seat so that their feet were not visible under the door – just as Wehrman Feeley’s daughter was demonstrating.

She had also tagged Moms Demand Action for Gun Sense in America, a non-partisan movement calling for “reasonable solutions” to gun violence.

Led by spokeswoman Lucy McBath, whose teenage son was shot dead, more than 300 supporters of the organisation had gathered outside the Capitol Building in Washington, DC, to show solidarity for Democrats’ sit-in demanding a vote on gun control.

The rebellion in the House began before midday on Wednesday and continued through a series of unrelated legislative proceedings into Thursday morning.

Coverage and photos of the protest spread fast on social media, buoyed by messages of support from Barack Obama and Hillary Clinton.

Thank you John Lewis for leading on gun violence where we need it most. https://t.co/vctfqAH5Wt

— President Obama (@POTUS) June 22, 2016

This is what real leadership looks like. https://t.co/4Nh6QpqSxL

— Hillary Clinton (@HillaryClinton) June 22, 2016

McBath told Guardian America that she was “deeply grateful” for the sit-in on the House floor and applauded those who had taken part.

“I’m a product of the civil rights era, and my father was a civil rights leader. I understand the power and authenticity of being able to move people for a cause – and Rep Lewis has demonstrated the passionate desire in our country for laws that will help save American lives from gun violence.”