The family of another of the victims, American Kurt Cochran, say they have been through a "humbling and hard experience".
The attack was carried out by 52-year-old Khalid Masood, a Britisher, as he rammed his auto into pedestrians on the bridge and stabbed a police officer stationed outside Parliament building as he tried to enter the premises.
Other victims of the terror attack were on-duty policeman PC Keith Palmer, 48, Leslie Rhodes, 75, and mother-of-two Aysha Frade, 43.
Mr Cochran had been with his wife, Melissa, on the final day of a holiday in Europe to celebrate their 25th wedding anniversary - their first trip overseas.
Mr Cochran suffered catastrophic injuries and died later that day, while his wife remains in hospital having suffered a broken leg and rib and a cut head.
The Cochrans, of West Bountiful, were spending their 25th wedding anniversary in Europe and concluded their trip in London to visit the woman's parents, who are now serving a mission for The Church of Jesus Christ of Latter-day Saints in the London England Temple.
Speaking at a United Kingdom press conference days after Cochran, a musician from Utah, was killed alongside three others in a terrorist attack at Westminster, his family described how Cochran lived a life of positivity.
Speaking at a press conference, family members said Mr Cochran and his wife Melissa had "fallen in love" with London during their first trip outside of the U.S. - part of their 25th wedding anniversary.
"We're just so pleased with the progress she has made in the past few days. We're trying to focus on positive things".
'It has been a tender experience for our family to be together with Melissa here.
"We can draw strength as a family from that. She is so grateful for the outpouring of love and generosity".
Jennifer Burton, another sister of Melissa's, said the family was focusing on getting Melissa strong enough to return home.
Friday, Britain's most senior counterterrorism police officer, Mark Rowley, said authorities are working to establish whether Masood, 52, "acted totally alone inspired by terrorist propaganda or, if others have encouraged, supported or directed him".
Just days before the referendum on June 23 previous year, lawmaker Jo Cox was killed by a loner obsessed with Nazis who shouted "Keep Britain independent" during an attack.
Meanwhile, police have released a 39-year-old woman arrested in east London on suspicion of preparation of terrorist acts in connection with Wednesday's incident.
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The Washington Post reported that two people suffered minor injuries; however, they did not require medical attention. KCBS reports that one person was pepper-sprayed by a demonstrator and another was punched.