Lesley Bradbury knifed Gary Moore after discovering he had unloaded several items she had packed in their car, Manchester's Minshull Street Crown Court heard.
Police called to the couple's home in Middleton, Greater Manchester, found Mr Moore bleeding from his left arm. Bradbury, a 50-year-old former invoice clerk, told officers: "He deserved it.".
Mr Moore, a driving instructor, was taken to hospital for treatment and has since made a full recovery.
Bradbury suffered from a mental health condition which caused her to hoard possessions and protect them in a "pathological way", the court heard.
She was initially charged with intent to cause grievous bodily harm but prosecutors accepted her guilty plea to a lesser charge of unlawful wounding.
Bradbury, who now lives in Stoke-on-Trent, was given 12-month prison sentence suspended for 18 months. She was also ordered to complete 30 days of rehabilitation.
Mr Moore refused to give a statement to police and it is thought the couple are still together.
The attack happened on 29 December as the couple packed for a holiday to see in the New Year.
Prosecutor Jonathan Turner said: “Police attended the home Bradbury shared with her partner and he was outside he had a two-inch stab wound to his left bicep. 'The defendant had stabbed him with a knife after he moved some of her belongings out of the car they were packing for a holiday. She said to police he deserved it and she wanted to kill herself.
“Inside the house he had thrown some of her possessions and she had stabbed him in order to stop him. There is no complaint from the complainant - he is hopeful for a renewal in the relationship.''
In mitigation, defence lawyer Richard English said: “Mental health issues underpinned the defendant’s offending. It is a case where if the defendant was well this wouldn’t have happened.”
Sentencing judge Paul Lawton, who had said at a previous hearing that Bradbury would not be going to prison, told her: “It has been difficult to get to the bottom of why you did this. You do have a psychological disorder that causes you to hoard goods and you need to protect those in a pathological way so you lashed out at him with a knife.
“But that doesn’t reduce your culpability - the knife could have gone into the chest and it could have been a different scenario. Your conduct has to be marked with a prison sentence but it won’t be an immediate custodial sentence.''
Lesley Bradbury knifed Gary Moore after discovering he had unloaded several items packed in car