"It just shows a very arrogant man.
"I don't understand how someone can go on the run for two crimes and be found guilty and still then just walk straight in with a very smug look on his face and claim innocence. It's unbelievable."
She said she found his claims of innocence "baffling".
She added: "The thing that I find quite baffling is he's still maintaining his innocence.
"Someone who's run away from this doesn't scream an innocent man's actions to me. Why did he run away if he's claiming innocence?"
A spokeswoman for the Georgian embassy in London confirmed Shepherd had surrendered himself to police and is being held in custody.
I feel very surprised at how smug he looks to be honest
Katie Brown, victim Charlotte's sister Scotland Yard said extradition proceedings to bring Shepherd back to the UK will be launched as soon as possible.
Charlotte's mum Roz Wickens, 53, told The Sun she now hopes her killer will finally face justice.
She said: "I'm just overwhelmed that he's been caught at last.
"It will never bring Charlotte back and the thought that he's just been sat there all this time is just - well - too much.
"There were times when I thought he would never be found.
"But I'm just so grateful to The Sun and everyone who's contributed to finding him.
"I just hope now he will be brought back to face justice as quickly as possible.
"It's not going to bring Charlotte back and my focus and drive now will be to change the laws to prevent this tragedy from ever happening again."
SPEEDBOAT KILLER FLED BEFORE SIX-YEAR SENTENCE Shepherd is wanted for the manslaughter of Charlotte Brown, 24, after fleeing the UK before he could be jailed .
The web developer was given a six-year jail term in his absence after being found guilty of her killing.
The Sun had offered a reward of £10,000 for information leading to Jack Shepherd's arrest.
Charlotte, of Clacton, Essex, died as the boat Shepherd bought to “pull women” flipped in the icy Thames on a champagne-fuelled first date in 2015 after meeting on website OkCupid.
Charlotte and Shepherd were thrown from the boat when it hit branches in the water near Wandsworth Bridge.
Shepherd was found clinging to the boat and Charlotte was pulled from the water unconscious and unresponsive.
Self-pitying Shepherd claims he fled the UK because Charlotte's dad Graham "threatened him" after he called to apologise.
The speedboat killer, wearing a wedding ring, said: “I’ve spoken to him only once, at which point he just took the opportunity to tell me that I would have a very bad time in prison.
"This was on the phone. I said, ‘I’m so sorry Graham’ but he did not want to hear it. He just hung up.
“So I feel at risk from him... and that’s the reason I ran away from the trial.
“I’m very very frightened of course but it seems this is the right thing to do.”
Checks revealed he arrived in Tbilisi, Georgia, on a Turkish Airlines flight from Istanbul on March 21 last year.
Sources confirmed his passport was scanned at Tbilisi's Shota Rustaveli International Airport at 3.31am.
Border officials added that his passport had not been used since, suggesting he was still in the country.
Georgian police launched a huge manhunt to arrest him.
Shepherd said he fled to the country because "there was a lot going for Georgia".
He added: "It was affordable, it had a generous visa regime, and it also had mountains and sea and it was just this country I'd always wanted to visit — I think the culture is very wonderful."
A spokesman for the Extradition Lawyers Association said it could take a very long time for Shepherd to be brought back to the UK.
They told : "I would imagine it will take an age. Unless he consents to extradition, it will largely depend on political will.
"There is very little extradition to or from Georgia. It happens very, very seldom and I can’t think of a single case."
Spokesman Saba Jikidze said earlier this week: “We cannot predict the length of the investigation, however, I can assure you that everything is being done by the Ministry of Interior of Georgia to find this person.”
Met Police chiefs were criticised for failing to act on information that Shepherd fled to the ex-Soviet Republic ten months ago .
His passport was scanned when he entered the country but he was allowed to vanish.