In The Witness for the Prosecution, Janet McIntyre was the maid of Emily French.
For the BBC 2 part series Janet's surname was changed to McIntyre and was younger to being the same age as Mrs French.
She is clearly devoted to her and when seeing Vole for the first time she is blunt to telling him that she goes through men so not to get comfortable, later on after French's death, reveals that she never hid her distaste for Vole despite the fact that he was there for good, she spied on him and tried to convince French to end the relationship by finding proof of Vole's wife which didn't work. She also saw Vole through the smog that night, the only thing that the defence lawyer suggests at that moment is that she is a lesbian and was mad in her devotion for French. However after Romaine was exposed Janet was re-questioned but upon the lawyer questioning her mind, she goes to answer back, but the inspector she spoke to earlier, signals her to stop which suggests to the lawyer that she was being coached and maybe influenced the verdict. After Vole being acquitted she tells John Mayhew that he has blood on his hands as she is pulled away. However Mayhew finds the corpse of Mimi the Cat while clearing French's house and declares that Janet was the murderer.
She is arrested and during the trial French's solicitor admits after the will change Janet came to him asking if Vole was guilty of murder what would happened to the estate and he reveals that it would return to it's former state which meant she would inherited a bigger amount. During her hearing she admits to kill Mimi, but due to her wording "it wasn't sorry" sound like she has a mental illness when the prosecution lawyer suggest that she was capable to kill French, she then breaks that she loved her and it seals her fate as the lawyer says that she was obsessed to kill her employer when she loved somebody else and due to her mind pinned everything on a innocent Vole. She found guilty and is hanged with her mind completely gone as she goes to the gallows.
She was played by Monica Dolan.