The family of Westminster attack victim Aysha Frade says she was "ripped away" from them in the "cruellest and most cowardly of ways".
Mrs Frade was one of four people killed by terrorist Khalid Masood in his 82-second rampage last Wednesday.
In a statement, her relatives told of their "crushing pain" and the "eternal void" which has been left in their hearts following her death.
The 44-year-old victim was described as a "guardian angel" who "never shied away from facing up to bullies".
Her relatives also said she was a "caring daughter, loving sister, amazing wife, irreplaceable aunt, thoughtful, supportive friend and the best and coolest of mummies".
They added: "We now pray that you guide and protect not only us, but all of London, from further evil.
"There are no words to even begin to describe the crushing pain and eternal void left in our hearts."
Mrs Frade and two other civilians - Kurt Cochran, 54, and 75-year-old Leslie Rhodes - were killed when Masood deliberately drove his car into pedestrians on Westminster Bridge.
The terrorist then fatally stabbed PC Keith Palmer, 48, in the grounds of Parliament before he was shot dead by another officer.
An inquest has heard PC Palmer died from a single stab wound to the chest, despite wearing protective body armour.
Police believe Masood acted alone but are continuing to investigate whether anyone else was involved.
Thousands of people linked hands on Westminster Bridge and police held a minute's silence outside New Scotland Yard on Wednesday, a week on from the attack.
Meanwhile, officers have released without charge a 58-year-old man who was arrested in Birmingham last week in connection with the incident.
They are continuing to question a 30-year-old man and a woman has been released on bail, while 10 have now been released with no further action.