Gun rights activist shot by own toddler son

A US pro-gun enthusiast has been shot by her four-old-son only hours after posting a message online about how "jacked up" he was to go shooting.

Jamie Gilt, 31, was driving in Putnam County, Florida on Tuesday with her son in the back seat when he picked up a .45 calibre pistol and shot her in the back, The Florida-Times Union reports.

Just hours earlier Gilt had posted on Facebook: "my 4-year-old gets jacked up to target shoot the .22".

Another post is of a girl holding a sign saying, "my parents are my armed bodyguards ... protect all the children with guns."

In other posts she professes her support for Republican presidential candidate Ted Cruz and calls for illegal immigrants to be forcibly deported.

She is recovering in hospital in a stable condition.

Putnam County police are investigating how the boy got his hands on the gun and have not ruled out Ms Gilt facing charges.

Under Florida law it is a crime for a person to store or leave a loaded gun "in a manner that is likely a child can gain access".

Officers who assisted Ms Gilt after she pulled to the side of the road said the boy was not strapped into his booster seat.