Sarah Williams, accused of the murder of businesswoman Sadie Hartley, has told a jury that her co-accused, Katrina Walsh, suggested delivering flowers to the home of the victim a week before the murder took place.
The prosecution said it was a "macabre test run" carried out as reconnaissance for the murder that Williams, 35, allegedly went on to commit in order to "get rid" of her love rival, Sadie Hartley, 60.
Williams, a ski travel firm sales adviser, is said to have driven to Ms Hartley's home in Helmshore, Lancashire, and tasered her with a 500,000 volt stun gun before stabbing her to death on the evening of January 14.
The defendant, who had had an affair with Ms Hartley's partner, Ian Johnston, 57, claims she was in bed ill at the time of the murder and that the evidence instead points to Walsh.
A week before the murder, on January 7, Williams and Walsh visited a nearby Tesco store in Haslingden where Williams bought a £3 bunch of chrysanthemums.
The prosecution said the aim of the night-time delivery in Sunny Bank Road was perhaps to see if Ms Hartley opened her front door, how she might be dressed or to make doubly sure it was her address.
Whilst giving evidence at Preston Crown Court, Williams said the pair had gone into Tesco to use the lavatory and that Walsh then asked if she had any money on her.
"At some point I said 'what idea' and and she asked me what Sadie looked like," Williams added.
"She said Sadie was renting a house in Helmshore near Ian. I asked her how she knew and she laughed, and in an expression she uses she said 'I have my ways'.
"There was more giggling and she said she wanted to know what she looked like. At the time it was a bit silly."
Williams said Walsh knocked on the door of the property and deliver the flowers whilst Williams waited nearby, out of sight, but not hiding.
The jury heard that Walsh mentioned Ms Hartley's name but replied she had forgotten who the sender was before disappearing down the drive.
Ms Hartley emailed her business partner the next day, saying the episode had been a "bit creepy" and "needless to say had a bad sleep last night as a result!"
Prosecutor John McDermott QC said: "You thought it was a giggly and girlie thing to do to the partner of the man you were throwing yourself at the time?"
Williams replied: "It was silly, it was ridiculous."
Mr McDermott said: "What is ridiculous is this story."
Williams said: "No, it's not."
Mr McDermott said: "It was pretty creepy what you were giggling about."
The defendant said: "It was certainly not intended by me to be creepy. Looking back, it was a stupid thing to allow to have happened."
Williams reiterated she had no desire to hurt Ms Hartley and added she had no particular interest in her either.
On January 12, Williams bought a pair of £19.99 men's steel-toecapped boots which were later discovered bloodstained at the workplace of horse riding instructor Walsh, along with the kitchen knife murder weapon and the stun gun.
Williams said Walsh suggested buying the boots as a birthday present for Mr Johnston and she later left them by mistake at her co-defendant's home.
The prosecution says Williams wore them to throw the police off the trail of a female assassin.
Williams, of Treborth Road, Blacon, Chester, and Walsh, of Hare Lane, Chester, both deny murder.