She bragged about her four-year-old's shooting skills - and the next day, her little boy shot her.

A US mother has been shot in the back by her four-year-old son after he found her .45 semiautomatic handgun on the floor of their family car and fired it.

Jamie Gilt, 31, had been driving when the gun was fired through the driver’s seat and up into her back.

Gilt was able to stop the car without causing any further injury before she attempted to catch the attention of a nearby police officer.

The accident came less than a day after an account that news sources believe to be her own had publicly bragged that her son loved to shoot in a post on Facebook.

“Thanks. All of ours know how to shoot too. Even my 4 year old gets jacked up to target shoot with the .22,” she wrote.

The Facebook page titled ‘Jamie Gilt for Gun Sense’ has since become flooded with users mocking the mother and her son for the event.

In the past 12 hours since the incident has been reported, spin off Facebook pages have emerged that take direct attack at not just Gilt but her son, too.

One page places a photo of Gilt and her son as the profile image with a photo of an American ambulance as the cover image.

The page encourages users to openly attack the mother by sharing posts that are meant to by read as though it is her son posting.

One particularly cutting post reads:

Users who have been taking the photos of her and her son to mock in memes and public posts have potentially been pulling them from the Twitter account that also shares her name, photo and location.

Police captain Joseph Wells told Jacksonville news that investigators are trying to determine whether or not the child had been strapped to the booster seat in the back of the truck.

“There was a booster seat in the back of the vehicle, but however the boy was not strapped in when the deputy got to them,” Wells said.

The shooting is being considered as accidental however it is not clear if Gilt will be charged. 

Click below to watch the full video news report.