The Victims Commissioner for London has described the sentence handed down to her stalker of 19 years as "an insult".
In October Elliot Fogel, 47, was found guilty for a sixth time of breaching a lifetime restraining order designed to stop him contacting Claire Waxman.
He was given a 16-month sentence but was released immediately as he had spent time in custody awaiting trial.
The Home Office said it takes its response to stalking "extremely seriously".
In an exclusive interview with BBC Newsnight, Ms Waxman said she was "absolutely shocked" by the punishment and is calling for a review of stalking legislation because she believes it isn't working for victims.
She said stalking is a crime of "psychological terror" which is "so invasive to all parts of your life that it changes you as a person".
"It's absolutely awful. What I'd gone through knowing he's been released since last week, the safety plans that had to be put in place for the children, their schools, my workplace and just all the things I have to now consider again. It takes its toll," she says.
Fogel's restraining order was first imposed on him in 2005. His stalking has including searching Ms Waxman's name in Google more than 40,000 times in one 12-month period, turning up at her work and home, and posing as a prospective parent at her child's nursery.
'Trauma'
In the latest incident, he sent a 20-page letter to Ms Waxman's employer, the Mayor of London, making false claims about her.
The mum of two has been diagnosed with PTSD as a result of the long campaign of harassment and says the recent occurrence was "retriggering".
"It's a wound... that is trying to heal. It doesn't take a lot to reopen and to really trigger the trauma, and take you back to where you've been years before," she said.
In 2021 there were 673,129 stalking and harassment offences recorded by police in England and Wales, according to the ONS. The Suzy Lamplugh Trust, a charity which supports stalking victims, estimates that 0.1% of cases leads to a conviction.
Ms Waxman believes the criminal justice system isn't taking stalking "seriously enough" and wants to see harsher tariffs for repeated breaches of restraining orders. On the second or third offence, the punishment should increase automatically, she says.
She also says the criminal justice system treats victims "appallingly".
"I know the system inside out. Not only as a victim, who's navigated it so many times over 19 years, but as the victims commissioner for London, hearing and supporting hundreds and hundreds of victims.
"I fought to get my rights. I got them because I can advocate for myself and I know what I should be entitled to. But no victim coming into the system's going to know that," she says.
'More exposed'
The government published a victims' bill earlier this year after promising a Victims' Law in its 2015 manifesto. Ms Waxman believes in its current form though, it doesn't "have teeth".
"Nobody is fighting for the victim. The police, they're there to investigate, the CPS are there to prosecute. And the victim's needs are very much an afterthought.
"The government draft victims bill would make no difference to any victim on the ground in its current status. We need to radically transform that and radically transform the way we treat victims," she said.
In the meantime, Ms Waxman fears her stalker may never stop.
"I don't think what's just happened to him would be a deterrent at all... and I feel more vulnerable and more exposed."
The Home Office said it has doubled the maximum sentence for stalking from five to 10 years, and it will require technology companies to act to address stalking content online through the Online Safety Bill.
"In January 2020 we introduced Stalking Protection Orders for police forces, a new civil order to protect victims of stalking at the earliest possible opportunity.
"We have also increased funding for victim support services to £460m over the next three years, and rolled out pre-recorded cross examination for vulnerable witnesses to help witnesses and victims give their best evidence," it said.
In 2021, the government announced that victim support services will see £185m in annual funding by 2024-25.