Patricia Smith clings to her father, police officer James Smith’s, hand at the ceremony awarding her mother’s Medal of Honour in 2001. Picture: News Corp

Patricia Smith’s mother, police officer Moira Smith, was the only female NYPD officer to die on 9/11 when the Twin Towers came down.

Patricia Smith became the girl in the red velvet dress: the image of the tiny two-year-old accepting her mum’s posthumous bravery medal, clutching her father Jim’s hand, broke hearts across the world.

It was three months after September 11, and the world was still reeling.

Little girl loss: Patricia Smith, 2 holds her father's gloved hand after accepting NYPD's highest honour, Medal of Honour for bravery, awarded posthumously to her mother Moira Smith, who was a police officer killed in terrorist attack on the World Trade Center in New York in 2001. Picture: News CorpSource:AP

Now, that little girl has become a teenager, and the 17-year-old used Mother’s Day to stare down one of the al-Qaeda terrorists she says stole her mother’s life, and almost 3000 others.

Patricia and her father, now a retired officer, went to Guantánamo Bay last Sunday to continue their pursuit of justice, Jim Smith told Newsweek.

“I am glad Patricia was able to accompany me here to see for herself the monsters responsible for the murder of her mother,” Mr Smith told Newsweek from Guantánamo Bay where high-level al-Qaeda operative, Yemeni Walid bin Attash, was attending pre-trial hearings for his role in allegedly planning the 2001 attacks.

“It will be her job to carry on the search for justice in the event I am unable to in the coming years.”

Patricia Smith is now a teenager. Picture: Matthew McDermott/NY PostSource:NY Post

Bin Attash is slated to go on trial alongside another al-Qaeda leader, Khalid Sheikh Muhammed, and three other alleged jihadis at Guantánamo Bay in the coming weeks, according to the Department of Defence.

He has been held at Guantanamo for almost 11 years.

The hearings started on Monday — the same day as Peace Officer Memorial in the US — a national day of mourning for fallen officers observed since 1962.

Moira Smith’s name is among the more than 20,000 slain police officials carved into the marble walls of the National Law Enforcement Officers Memorial in Washington, DC.

REMEMBERING OFFICER MOIRA SMITH

A name etched in marble can’t tell the full story of her heroism.

But it is summed up in an iconic picture from September 11 of her helping a blood-soaked Wall Street worker Edward Nicholls — one of more than a dozen she helped save — out of the South Tower of the World Trade Center.

She returned to the tower, and was swallowed up and crushed by the rubble when it collapsed.

They found her NYPD badge, and her gun holster with her house keys attached in the death zone. She was 38.

In 2014, as a portrait of her mother was unveiled at the 13th Precinct station house in Manhattan where she was based, Patricia admitted all she knows of her mother is what others have told her.

“That’s probably the hardest part and that’s the part that makes me the most upset, is the fact that I can’t remember that much,” the New York Daily News reported.

“Actually, I can’t really remember at all, no matter how much I try. But at least I know stories.

“At least I have so many people that will tell me incredible stories of bad moments and good moments.”

Police officer Moira Smith helps Edward Nicholls, 50, from the south tower of the World Trade Center minutes before its collapse. She re-entered the building to assist others in the evacuation and was killed. Picture: Corey Sipkin/NY Daily News Archive via Getty ImagesSource:Getty Images