Mrs. Vandemeyer laid down the revolver on the edge of the washstand within reach of her hand, and, still eyeing Tuppence like a lynx in case the girl should attempt to move, she took a little stoppered bottle from its place on the marble and poured some of its contents into a glass which she filled up with water.
Mrs. Vandemeyer kept the gun near her while she drank water. 
Mrs. Vandemeyer threw the gun at Tuppence and asked her to drink water with her. 