Her arrest came after militant protesters allegedly tried to drive a lorry at a line of police. Two men held in connection with the allegation were released without charge.
An estimated 1,000 police in riot gear, including dozens of mounted police, were involved in clearing Trafalgar Square of about 1,500 demonstrators who refused to leave the area.
Sixteen people have been charged with various public-order offences, including assault and criminal damage, and are due to appear at courts in London today. In all, 29 people were arrested amid clashes outside Downing Street and in Trafalgar Square.
The Liverpool Dockers' Support Group was joined at the rally by the anti- car movement Reclaim the Streets and other environmental groups.
Police stressed that the violence did not appear to involve the striking Liverpool dockworkers, many of whom brought their families with them for their Social Justice March, during which a petition was handed in at Downing Street.Reuse content