Julie Beards admitted inviting 20-year-old Susan Whiting to her bungalow in Heather Close, Bloxwich, in August last year knowing that her husband planned to rape her.
The two women, both with learning disabilities, had met at Walsall Adult and Community College.
A judge said Beards, 36, was 'suggestible' and controlled by her husband but knew what she was doing was 'very wrong' and had done nothing to prevent it.
Steven Beards was jailed for 33 years in May after being found guilty of the rape and murder of Ms Whiting.
The same jury cleared his wife of murder under joint enterprise, instead convicting her of manslaughter, but failed to reach a verdict on the charge of aiding and abetting rape.
She faced a fresh trial but at the last minute pleaded guilty on the basis she played a lesser role than was originally stated.
Susan Whiting was found dead under a bed at the Beards' home two days after visiting for a sleepover.
She had been drugged before being raped by Steven Beards who then strangled her and delivered three fatal hammer blows.
During his trial, he was described as someone with a history of sexual violence with 'sadistic' tenancies', having been accused of raping, abusing and trying to kill his wife in the past.
At Birmingham Crown Court on Wednesday, Mr Justice Green accepted that Julie Beards was 'genuinely scared' of her husband and inclined to do what he said out of fear.
He concluded her culpability was low but that she could have persuaded Susan not to come.
He also said she also knowingly helped her husband hide the body and lied to the police.
Justice Green described Ms Whiting as a 'vibrant and loving' woman who was extremely vulnerable because of her learning disability and trusting nature.
But he took into account that Julie Beards had been described as 'babyish' with a mental age of nine.
Passing a combined sentence of seven years and three months, he told her that she had played her part.