Mohanna Abdhou was shot in Malvern Road, Kilburn, on Friday night and died at the scene.
In a statement her family said they were "heartbroken at the loss" of their "loving daughter".
Ms Abdhou, known as Montana, was approached by "two males" on bicycles who fired "shots at her group".
A post-mortem examination on Saturday gave the cause of death as a single gunshot wound.
Her family said: "We are truly saddened, heartbroken and still in complete shock that we have lost a beautiful and caring soul.
"No words can truly express our feelings towards this situation.
"She was a loving daughter, sister and friend. She was loved by everyone and her warmth and kindness will be remembered fondly."
Det Ch Insp Andy Partridge said police had found nothing in Ms Abdou's background "which gives any suggestion she would have been a target".
The two suspects have been described as being of medium build and dressed all in dark clothing.
Police said their faces were covered, which "would have made them stand out on such a warm evening".
The family of a woman shot dead by two cyclists have paid tribute to the "beautiful" 20-year-old who was "loved by everyone".