Maureen Lynch, 55, of Park Street, will appear at Tower Bridge Magistrates Court on Tuesday charged with theft.
Lynch, the former treasurer of a national anti-gun crime organisation, has been charged with stealing funds donated to the group.
She is a former officer of Mothers Against Guns, which lobbies for tougher sentences for those convicted of firearms offences.
Scotland Yard confirmed to the BBC that Mrs Lynch, who is unemployed, is alleged to have taken the money from the group's Royal Bank of Scotland account between March and September 2004.
Mothers Against Guns was set up by Lucy Cope in 2002, following the death of her son Damian, and is funded by grants and donations, including money from the Home Office.