Cristea, 31, was on holiday with her boyfriend in London when she was thrown off Westminster Bridge during the March 22 attack. London police said she died Thursday when her life support was withdrawn.
"After fighting for her life for over two weeks, our beloved and irreplaceable Andreea - wonderful daughter, sister, partner, dedicated friend and the most unique and life-loving person you can imagine - was cruelly and brutally ripped away from our lives in the most heartless and spiritless way," her family said in a statement.
Cochran, 54, was an American who was in London with his wife celebrating his wedding anniversary, a family member told ABC News. Kurt and Melissa Cochran, who live in Utah, had been married for 25 years. Melissa was injured in the attack.
Palmer was a 48-year-old British police officer. He was married with a 5-year-old daughter.
The Metropolitan Police released a statement on behalf of his family that described Palmer as "dedicated to his job and proud to be a police officer, brave and courageous."
Frade, 43, was on her way to pick up her two daughters from school near the Westminster Bridge, according to ABC News. Frade worked on the administration team at DLD College London.
The school released a statement on Thursday:
"We are all deeply shocked and saddened at the news that one of the victims yesterday was a member of our staff, Aysha Frade. All our thoughts and our deepest sympathies are with her family," said Rachel Borland, the principal of DLD College London. "We will be offering every support we can to them as they try to come to terms with their devastating loss."
ABC News reports that a fourth victim died on Thursday after life support was withdrawn. He was a 75-year-old man who had sustained injuries in the attack, but police did not give any more details about his identity.
Editorial Note: An earlier version of this story identified Kurt Cochran as Kirk Cochran in a photo caption.
The Associated Press contributed to this report.