Elsie Rossiter was an elderly woman who lived in a block of flats. George feared her due to thinking she was a witch. While taking the rubbish out one night, she was sucked into the dollhouse because George's psychic powers were running out of control. In the dollhouse, she was hunted by the peg dolls, who caught her and turned her into one of them. Though unlike Purcell and Amy. It's unconfirmed which one she was though it can be speculated she was turned into the Pirate Doll as he (she in this case) was not present until Rossiter was seen being hunted by them.
When George faced his fear, she was transformed back to her old self and returned to the council estate. She considered the memories of her ordeal to be a dream, commenting "must be them tablets." (TV: Night Terrors)