Carrie Dilcock also started a fire at her partner's home and spat at a police officer on one occasion when she was arrested.
Leeds Crown Court heard how Dilcock carried out the offences between June and October last year.
Timothy Jacobs, prosecuting, said the victim lived next door to Dilcock's partner.
In June last year she wrongly formed the opinion that her partner was having an affair with the woman.
The prosecutor said: "She was on the receiving end of abuse in person or text threats.
"On one occasion the abuse involved a racist slur."
The offending continued and Dilcock subjected to the woman to further threats on July 25 when she was locked out of her partner's home.
Dilcock was seen banging on the door of his home and the neighbour called the police as she thought the defendant was trying to break into the property.
While waiting for the police Dilcock threatened the victim with violence.
Police officers arrested Dilcock outside the house and she was taken to Elland Road police station.
As she was being escorted into the building she spat at one of the officers and it landed on her hair and glasses.
The arson offence took place on October 2.
A call was made to the fire service at 9pm reporting a fire at Dilcock's partner's home in Armley.
Firefighters went to the house and Dilcock was inside the property.
The firefighters encouraged her to leave the house but she refused.
Mr Jacobs said the firefighters then made attempts to get inside the house but she tried to kick away ladders placed against the building in a bid to rescue her.
Dilcock eventually left the house and the officers discovered that a mattress had been set alight when they went inside.
The firefighters put the fire out and Dilcock was arrested again.
The 33-year-old defendant claimed that she had started the fire by accident.
Dilcock, of Old Run View, Belle Isle, pleaded guilty to arson being reckless as to whether life was endangered, racially aggravated harassment, assaulting an emergency worker and threatening behaviour.
The victim provided a statement to the court describing how she had suffered nightmares and flashbacks as a result of Dilcock's offending.
She also described how she had been frightened to leave her home.
Stephen Littlewood, mitigating, said Dilcock was sorry for what she had done and that the offences were linked to her misuse of alcohol.
Dilcock was given a two-year prison sentence, suspended for two years.
She was also ordered to take part in a 12-month alcohol treatment requirement and to complete 30 rehabilitation activity requirement days.
Judge Robin Mairs said:"If you do not put you back into this (order) you will be in breach.
"Any breach brings you back to me and I will send you to New Hall (prison).
"You had it in your head that your partner was in an intimate relationship with her and you made her life a misery.
"You bombarded her with threats and messages and on one occasion she had to leave her house to hide from you.
"When in drink you are a nightmare to live with and live beside."