A mother who was found guilty of allowing the death of her baby at the hands of his father has been jailed.
Laura Davies, 25, of Walnut Close, Bilston, West Midlands, was sentenced to 18 months for allowing the death of six-month-old Kayden Walker.
Kayden suffered a "catastrophic brain injury" after being shaken by Ricky Walker, who was jailed for six years.
Davies had failed to protect her son and "heed warning signals", a judge said.
The trial at Birmingham Crown Court heard how Davies, who has a history of mental health issues, argued with 27-year-old Walker, but failed to inform police of "warning signals", after he said "let's see how long it takes for him [Kayden] to suffocate".
Last month, Judge Mr Justice Morris said Walker had "forcibly shaken" and hit his son's head on a hard surface.
Kayden went into cardiac arrest at home on 12 June 2016, and was pronounced dead in hospital about an hour later.
Passing sentence on Davies, Mr Justice Morris told her on Wednesday: "You failed to take such steps as you could reasonably have been expected to take to protect Kayden.
"He was only six months old and you left him in the sole care of Ricky Walker in the flat and you failed to heed warning signals arising from Ricky Walker's behaviour."
Davies was convicted last month of allowing Kayden's death after prosecutors alleged she was aware of previous incidents of violence by Walker.