Lesley (Invasion of the Bane)

Lesley was the PA and secretary to Mrs. Wormwood at the Bubble Shock! factory. She tried to kill Sarah Jane Smith in a lift, but was unsuccessful and Sarah Jane subsequently escaped. Injured, Lesley went back to Mrs Wormwood and told her that Sarah Jane escaped. (SJA: Invasion of the Bane)

Since every Bane that fails in its mission is devoured by the other Bane its likely this happened to Lesley.