Leisl Smith, 23, vanished from Tuggerah train station in 2012.

It’s a question her mum, Sandi Harvey, has asked every day since her 23-year-old daughter vanished without a trace from the New South Wales Central Coast just over three years ago.

“I have scenarios going through my head that no mother should ever have to think of,” Ms Harvey told news.com.au

“I don’t think anyone has put a story to me that I haven’t thought of myself.

“I’ve imagined scenarios where she had an accident or where something happened to her and the person she was with got rid of her, right through to her being like one of those young girls in America locked in a basement for 10 years before they’re discovered, and all the stories in between.”

Leisl Smith drove away from her father’s Wallarah home about 1pm on August 19, 2012.

She was last seen on CCTV footage getting into a white Ute at Tuggerah Railway Station carpark about 2pm that day.

“We don’t know why she went there,” Ms Harvey said.

“It wasn’t like her. If she was going to meet someone she’d meet them at a local hotel, to catch up for drink or something like that.”

Leisl Smith, 23, vanished from Tuggerah train station in 2012.Source:Supplied

23-year-old Leisl Smith has been missing since 2012.Source:Supplied

Police were called by concerned family members when Leisl failed to return home and could not be contacted.

Despite an extensive investigation by detectives from Strike Force Wehl involving numerous property searches she has not been seen since.

Leisl’s Honda Accord was discovered abandoned in the car park at Tuggerah train station about a month later on September 26.

“Why she’d go to Tuggerah station and leave her car there is a bit odd,” Ms Harvey said.

The driver of the car Leisl was seen getting into was identified as a 43-year-old Wallarah man who police deemed a ‘person of interest’ but was never charged in relation to her disappearance.

Family and friends have repeatedly stated that Leisl’s disappearance was completely out of character.

“She loved animals and won lots of ribbons for horseriding … one of her horses, Molly, was due to have her foal when Leisl went missing and there’s no way she would have missed that because it was so important to her,” Ms Harvey said.

One of Leisl Smith’s beloved horses was due to have a foal when she went missing.Source:Supplied

Leisl’s bank accounts have not been touched. According to police, she had her mobile phone with her at the time of her disappearance.

Ms Harvey said two text messages were sent to Leisl’s father after she vanished but that it was never proven her daughter was the sender.

Police have previously treated the case as homicide although a body has never been found.

NSW Police Senior Constable Angela Corbett today told news.com.au the investigation was still ongoing, but had reached a standstill.

She said no new leads or information had been received in more than a year.

“Nothing is different,” she said.

Ms Harvey had fallen out with Leisl a year before she vanished and never got the chance to reconcile.

“We’d had an argument and she wasn’t talking to me,” she said.

“If guilt could be written from here to the moon, that’s how guilty I feel.”

Ms Harvey said she bought her daughter birthday and Christmas present each year and kept them wrapped and in a corner of her home in the event Leisl returns.

“I don’t believe she’s alive,” she said.

“But then you never know so I have to hold on to two per cent hope that she may walk back in door one day.”

Ms Harvey told news.com.au she had printed missing persons flyers and handed them out at train stations in a bid to find her daughter and was now appealing to the public to help solve the case.

“What I’d like is to try and get it so at the end of every 6pm news bulletin a missing person is mentioned after the news,” she said.

“In America they have millions of cartons with pictures on them.

“I’m not saying we have to put faces on milk cartons but if we could just mention one missing person a night it could go a long way to stop them from falling off the radar and to help finding them.

“It’s not like there’s not a lot of missing persons out there and it only takes one person to come forward.”

A missing persons page has also been setup for Leisl.

“The more people that share it around the better chance someone who knows something will see it,” she said.

“I know every time I hear someone has gone missing or a body has been found, my heart just breaks for the family because it’s certainly not a club that you ever want to join.”

Ms Harvey said Leisl, one of six children, was a “happy, go-lucky” character who “didn’t let a lot of things get to her”.

Leisl had aspirations to be a veterinarian and work predominantly with horses.

“She loved animals more than people and she didn’t ever seem to have barriers to anything she could do, nothing was ever a real problem for her,” Ms Harvey said.

“She was always independent and lived in her own world.

“I just want someone to tell me where she is or what’s been done with her.”

Anyone with information about Leisl Smith’s disappearance is urged to contact the Police Assistance line on 131 444 or Crime Stoppers on 1800 333 000.