William and Kate met the parents of Elsie Dot Stancombe, seven, Bebe King, six, and Alice da Silva Aguiar, nine, as they were welcomed by pupils at two schools which the girls attended on Tuesday.
The girls were killed in the attack at the Taylor Swift-themed dance class on July 29 last year.
Visiting Churchtown Primary School, which Alice and Bebe attended, the couple were shown around a new playground which was built in their memory after a fundraising campaign.
William and Kate spoke with pupils during a visit to Churchtown Primary School in Southport (Phil Noble/PA)
In a speech in front of the school’s 700 pupils, William said: “This playground is a symbol of how the community have come together to create such a positive space for the pupils of this school – a symbol of remembrance and resilience, a testament that love will always overcome tragedy.”
He said the teaching communities at the school and at Elsie’s school Farnborough Road, which they visited earlier in the day, had gone “above and beyond to help heal this incredible group of young people”.
He added: “To Alex and Sergio, Lauren and Ben, Jenni and David – you are parents united in grief. You have faced such horror – but from that you move forward with grace and fortitude, creating the most remarkable legacies for your girls. We will always be here to support you.”
Speaking afterwards, Bebe’s mother Lauren, 42, said: “It meant everything. It was really special.
“I think we’re really grateful anyway how Bebe’s been honoured so much in this school and seeing the prince and princess support that and be here has been just amazing.”
William and Kate had private meetings with Mrs King and her husband Ben, 43, as well as Alice’s parents, Sergio and Alexandra Aguiar, when they arrived at the school.
The royal couple were shown the new playground built in honour of Bebe King and Alice da Silva Aguiar at their school (Phil Noble/PA)
For the rest of the visit the couple wore friendship bracelets given to them by the Kings which said Bebe’s Hive, the name of the charity set up in her memory.
They spoke to Alice’s classmates about artwork they had done which was inspired by their feelings, and were then shown around the playground.
The Aguiars showed William and Kate the stage area, which had been built for students with a love of performing.
Mrs Aguiar, 34, said: “Prince William asked if that would be her favourite place and I said yeah, she would have been there dancing away.”
She said the visit had given pupils a “day they will never forget”.
Mr Aguiar, 38, added: “It’s so special to have them here to support us.”
Mr and Mrs King showed them a wooden wigwam built in the playground which is named The Hive and has the words “Remember Bebe” on it.
The Princess of Wales chatted to pupils during the visit to Farnborough Road Infant and Junior School, where Elsie Dot Stancombe was a pupil (Eddie Mulholland/Daily Telegraph/PA)
The families have met the couple before and Mr and Mrs King said they were “really welcoming, really warm”.
Earlier in the day, the royals visited Elsie’s school, Farnborough Road Infant and Junior School, in the town.
They spent more than an hour at the school and around 30 minutes meeting Elsie’s parents Jenni, 36, and David Stancombe, 37, during a private meeting.
Kate wore high-waisted dark grey trousers and a pink blouse, with a matching grey woollen trench coat and grey court shoes.
William wore a navy suit and pale blue shirt.
Headteachers at the school thanked the royal couple following what they described as a “tremendously stressful” year, after the attack left the local community devastated.
Jennie Sephton, head teacher of the infant school, said: “It’s made such a big difference.
“It was something that Jenni and David wanted them to do right from the beginning.
Kate was given flowers on arrival at Farnborough Road Infant and Junior School (Eddie Mulholland/Daily Telegraph/PA)
“It was around the recognition of what staff have done, how they have supported the family, how they have supported the children going forward.
“And it’s just real recognition that they value Jenni and David but they have also listened. It’s just so special.”
Adrian Antell, head of the attached junior school, said: “They spoke so wonderfully about what this community has done together, and they thanked this community for the work they have done, I think that’s really important we get that out.”
William and Kate carried out the visit to Southport to show their ongoing support for families and the community after last summer’s fatal knife attack.
It is the second time they have been to Southport in the wake of the attack and subsequent widespread rioting.
The royal couple delivered hugs and sympathy after meeting the families of the three girls on a visit to the town last October, where they also praised and thanked emergency workers who responded to the attack.
Cameron Smith, 11, and Ellis Paynter, 10, were among the children who greeted the royal visitors.
Ellis said: “We were shocked, I was like, ‘We get to talk to the prince?’”
Jessica Hazelhurst, 10, said: “All of the teachers didn’t get to find out until break time. We all came into school thinking we were getting photos for school council but then it was this.”
Zainah Thompson, 10, said: “We were all very nervous. We talked about what our favourite lessons were.
“He said he wasn’t good at maths, but said it’s a good subject to learn.”