Rachel Beeton went to confront Kayleigh Ward in November last year after receiving the message but got the wrong address.
Instead she called at the home of one of Ms Ward’s neighbours at Riverside Court, Louth, and banged on the doors.
Lucky Thandi, prosecuting, said “Another neighbour called the police. The defendant grabbed a wooden broom and smashed the window.
“She continued to scream and bang outside the property for 10 minutes before walking away.”
Beeton went home and returned armed with a knife.
This time she entered Ms Ward’s home and slashed furniture including a sofa, chairs and a mattress. Blood staining was found on a number of items in the property.
Miss Thandi said police were called out again and found Beeton in an agitated state. She kicked out at an officer, catching him in the ribs, and he suffered cuts to his arm and a thumb while she was being restrained.
When Beeton was later interviewed she told police she had drunk three or four cans of lager and reacted after receiving text messages.
Subsequent to the incident, Beeton was given an eight-week jail sentence for a separate matter in which she damaged her ex-husband Andrew’s car.
While she was in custody she rang him from Peterborough Prison on a number of occasions and also wrote letters to him despite being under a court order not to contact him.
Beeton was arrested again but told police she had no malicious intent in contacting her ex.
Then, in March this year, while still in custody, she wrote a letter to a friend telling of her plans to kill both her ex-husband and his partner.
Miss Thandi told the court that the letter was intercepted by prison staff.
She said: “In the letter she said she would put a knife right through her ex-partner Mr Beeton and his new partner.
“She detailed how she was spending her nights planning to kill Kayleigh Ward.
“Later she was further interviewed by police. She said she intended sending the letter. She went on to say she had every intention of killing Kayleigh Ward on her release from prison.”
Rachel Beeton, 35, of St Bernard’s Avenue, Louth, admitted charges of criminal damage, possession of a knife, assaulting a police constable and obstructing a police constable in the execution of his duty as a result of the incident at Riverside Court, Louth, on November 13 last year.
She also admitted harassment in contacting her former husband in breach of a restraining order and pleaded guilty to a further charge of attempting to make threats to kill on March 19 as a result of the letter she wrote to her friend.
She was given a four year jail sentence and following her release will remain on licence until 2025.
She was also given a 10 year restraining order.
Judge Andrew Easteal, passing sentence, said: “You made no bones about the fact that you wished to kill Miss Ward and possibly Mr Beeton.
“The letter and the interview are chilling in the casual way you expressed a ruthless and violent determination to hold both of them to account for the blame you attribute to them for the turn your life has taken. I have not the slightest doubt that you meant every word and that remains your view.”
Chris Jeyes, in mitigation, said Beeton had been very honest about her feelings.
He added: “The threats to kill made both in the letter and in the police interview are to some extent a thought crime.
“The threats contained in the letter were intermixed with all sorts of other comments.”