Ms Doyle disagreed she wanted the farm to be divided up and sold. "I am doing this to get justice for Michael".
She denied this dispute had arisen because she was angry that Michael had made a will and she was now making sure that legal costs would be run up to ensure Richard did not get it.
Earlier, she told her own counsel Michael Counihan that her family and Ms Cooper's family had been close as they all lived within a short distance of each other in Enniscorthy.
After Michael first got sick in October 2010, around Christmas that year, Ms Doyle said she was told by Michael: "Would you believe she (Sheila) sent down Dick (Sheila's husband) for me to give the place to Richard".
Ms Doyle said her brother added "it won't be happening".
Asked did she know how Richard and Michael got on, she said they were "always squabbling" and on one occasion Ms Cooper told her the two men were "at each other's throats again".
She took no notice until she heard later that Richard had knocked Michael to the ground, a claim which Richard has strongly denied in court.
She said Michael "had no time for the Coopers" even before Ms Cooper married Dick because Michael "knew Dick's father and their relations were just up the road from us".
There was never any mention of a will until a few days after Michael was buried, she said.
Ms Cooper arrived in Ms Doyle's house and said "by the way Richard got the farm". When Ms Doyle expressed surprise, her sister allegedly said "you are making me very angry".
She added: "This was not the Sheila I knew and I told her to stop shouting at me and I was very upset".
She believed the will should never have been made because Michael was not capable of doing so.
Bobby Buckley (48), a son of Joseph, was another nephew who said that like Richard he worked on his uncle Michael's farm as he was growing up and into adulthood.
He said at a family gathering in his home after Michael got sick, Ms Cooper brought up the question of a will. "I don't remember her exact words but she said I want Richard to have it and I remember her tapping her finger on the table".
In relation to an alleged altercation between Richard and Michael, Bobby said Michael called him to the farm and told him Richard had "come down shouting and roaring that he was up to his eyes in debt". He said Michael pointed to the ground and said "He (Richard) put me to the ground here the other day".
Dick Cooper, Ms Cooper's husband, said he did not think it was unusual for him and his wife to call to a local solicitor's home to ask him to take the will at 8pm at night. He said they just happened to be passing by.
When that solicitor found Michael did not have testamentary capacity, he (Dick) called the firm Jason Dunne worked for because the office was just up the street from his workplace. Mr Dunne found Mr Buckley's condition had improved and he successfully took the will.
Evidence has ended and the case was adjourned for parties to make legal submissions.