Violet's Friend Sister Kate : Season 1 Episode 8

Violet's Imaginary friend comes to visit and has the gang in an uproar. Violet get upset when the others pretend to see her, and she runs away. Sister Kate gets a phone call from a local hospital telling her Violet is there. Violet went to the hospital because that is where she last saw her friend alive. The friends invisible counterpart is how Violet coped with the death.