The twisted suicide bomber killed 22 people and injured dozens more when he detonated a bomb packed with shrapnel in an Ariana Grande concert.
"It's awful. Very wicked to target that sort of thing", she told Evie Mills, 14, and her parents.
"The focus is still the search for accomplices and the network but he could have made this bomb himself", the source said.
It came after security footage emerged of the bomber, 22-year-old Salman Abedi, walking through a city shopping centre wearing the backpack he used to carry the explosives in the days before the blast.
After Trump defended his decision to discuss intelligence with the Russians during a White House meeting, Prime Minister Theresa May said last week that Britain would continue to share intelligence with the United States.
Among those in custody is Abedi's brother Ismail, who was arrested in Whalley Range, south Manchester, on Tuesday.
"I want to reassure people that the arrests that we have made are significant, and initial searches of premises have revealed items that we believe are very important to the investigation", he said.
"Many experts, including professionals in our intelligence and security services, have pointed to the connections between wars our government has supported or fought in other countries, such as Libya, and terrorism here at home", Corbyn said in his first speech since Monday night's atrocity.
British counterterrorism officials confirmed Thursday that they have resumed intelligence with the USA after receiving "fresh assurances" that it would not be leaked.
Abedi had been banned from his local mosque for interrupting a sermon an imam was giving against Islamic State.
A MIDLETON dad who escaped the Manchester Arena with his wife and son has said he feared that the terrorists would invade the concert venue to massacre people in a Bataclan-style attack.
"If it's going ahead, I think we'll be alright", he told AFP, remembering the "fantastic" atmosphere of previous races.
"Abedi was one of a larger pool of former SOIs whose risk remained subject to review by MI5 and its partners", he said. British officials, however, have not commented on whether Abedi had links to IS or other extremist groups.
"Eight men remain in custody for questioning".
In the note, Grande also praised her fans for their response to the incident, which left 22 people dead and more than 60 injured, including several children and teens.
Armed troops have been sent to guard key sites, a rare sight in mainland Britain.
The attack was the deadliest in Britain since 2005 when four suicide bombers attacked London's transport system, killing 52 people.
Political campaigning for the June 8 national election which was suspended after the Manchester attack resumed on Friday with the bombing becoming a central feature.