Caroline Criado Perez said it was "great" that Twitter had taken a "first step" in dealing with harassment on the social media site, but said more needed to be done.
Ms Criado Perez, from north London, was one of a number of women who were subjected to a torrent of abuse by Twitter users last month.
Ms Criado Perez said: "It's great that Twitter has listened.
"There are still issues: users have to agree for the report to be potentially shared with the harasser, and there are some boxes that could be auto-populated that aren't. But overall, this is a fantastic first step."
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Two members of the public were injured along with two police officers who were in the unmarked vehicle.
Scotland Yard recorded 1,235 Islamophobic attacks in the last 12 months, compared with 811 in 2015.
Officers say the child, aged two, was targeted in the Lewisham Shopping Centre.