The family of a missing mother have shared a plea online for anyone with information about her disappearance to come forward.

Jana Armstrong, 30, was last seen at a unit on Gordon Avenue in the Toowoomba suburb of Newtown, southeast Queensland, on Tuesday afternoon.

Family said the disappearance of the mother, who has a four-month-old child, is very out of character.

Ms Armstrong’s white Hyundai Kona was found on the corner of Jellicoe Street and Gordon Avenue about 6am on Wednesday.

Police and loved ones are concerned for her welfare.  

The Courier Mail on Thursday reported forensic officers attended a home on Gordon Avenue.

Neighbours saw officers talking to a man outside the Newtown unit before both drove away in a marked police car.

Ms Armstrong’s sister asked anyone with information to contact police.

Jana Armstrong (above) was last seen at a unit in Toowoomba on Tuesday

Queensland Police and SES searched large areas of Toowoomba on Thursday

She wrote online that she was ‘extremely concerned’ for her welfare. 

‘I’ve had a lot of people asking for more information and where (her son) is – I have (him) and he is safe.

‘Please if you know anything reach out.’

Ms Armstrong’s’s friend Amelia Street told the ABC the missing mother worked as a carer.

‘She is such a gorgeous soul. She is an angel on Earth,’ Ms Street said.

‘I am absolutely desperate.’

Police and SES crews searched multiple areas of Toowoomba on Thursday.

That included Black Gully Reserve, about 500m from where forensic officers were seen.

Ms Armstrong is described as Caucasian, about 165 centimetres tall, with blue eyes and brown hair. 

Anyone with information on her whereabouts is urged to contact Crime Stoppers.