George Thompson's grandmother

George Thompson had a grandmother, whom was familiarly known to him as Nana.

When George was little, Nana gave him some toys, that George found creepy. The toys, including metal soldiers with "bad" faces that made him feel "funny", were subsequently locked inside his cupboard. (PROSE: My Special Book)

Behind the scenes
It is not clarified whether Nana is the parent of Alex or Claire Thompson in PROSE: My Special Book.