Davidia and Grandma's Memories

Davidia and Slirander had the 'single' task of researching Slirander's grandmas memories for a school age based thesis. Not much was known about her history. Her memories were stored in a secret place inside the room with the waving hands wall.
What secrets did those memories hold? Was there danger attached to them?
Their journey of discovery took them to the land of the memory eaters, clandestine operations in World War Two, scrubbing floors in a boarding school, witnessing a banned pugilistic competition, a stint in prison, almost blended as staff into a seedy western saloon, tricked into being an almost working class girl and lost in a desert.
Who was the real grandma?
Was she the vivid storyteller as Slirander remembered or was another truth hidden within the grey haired old lady with the road map face and non-fashionable attire?
The girls completed their age thesis at school; however, one memory had a twist concerning a revelation that implicated the British Government. It was labelled 'Top Secret'. What was the secret from the past?