The incident, which took place on Boxing Day, occurred at Talmud Torah Machzikei Hadass School, an independent school for boys aged between 3 and 16.
Hackney police were assisted in their arrest by the Shomrim neighbourhood watch.
Rabbi Herschul Gluck, president of Shomrim in Stamford Hill, told the JC the arrested woman was mentally ill, but also antisemitic.
Somali community group Coffee Afrik CIC said on Twitter she was “well known” to social services and had a history of severe mental illness.
