But Willis was still hired just weeks after Rachel MacNeill's mother, Michele MacNeill, had died to care for her younger sisters.
But instead of attending to the small children, Rachel MacNeill, 34, testified on Thursday that Willis' focus was instead on her father, Martin MacNeill.
"I expected her to be focused on the children, to cook or clean or take care of the children," Rachel MacNeill testified. "[Instead], my dad was cooking, she was staring at my dad. There was nobody looking after the children."
In the weeks after Willis moved into the MacNeill home, Rachel MacNeill said it became clear to her that Willis did not have a merely professional relationship with her father.
"It was obvious," she testified on Thursday in Provo's 4th District Court. "She was just goo eyes at my dad and wouldn't do anything a nanny would do."
Martin MacNeill, 57, is on trial for murder and obstruction of justice for allegedly killing his 50-year-old wife in order to continue an extra-marital affair with Willis, who is now 37. He is accused of giving his wife a fatal combination of prescription drugs after she came home to recover from cosmetic surgery.
Michele MacNeill was found unconscious in a bathtub by her 6-year-old daughter on April 11, 2007. Ada MacNeill found her mother fully-clothed and face-up in the bathtub, according to the girl's preliminary hearing testimony. The child went to a neighbor's house to get help, and eventually Michele MacNeill was pulled from the bathtub by a neighbor and Martin MacNeill. The two attempted CPR before medical crews arrived.
Those medical crews also attempted to perform CPR and other life-saving efforts before Michele MacNeill was taken to the hospital, where she was pronounced dead.
Rachel MacNeill, 34, testified Thursday that she rushed to her parents' Pleasant Grove home after missing several calls from her father that April day. Later in the evening, her father insisted that he show her in detail how her mother was found in the bathtub.
"My dad was adamant that he describe what happened," Rachel MacNeill testified. "I told him I didn't want to know, he insisted."
Martin MacNeill took her into the bathroom and told her that Michele MacNeill was found with her legs sticking out of the tub, face-down, with her head underwater.
"It was horrible," Rachel MacNeill said between sobs. "I didn't want to know. My mom was dead and I was concerned about my family. I didn't want to hear all this."But Martin MacNeill's explanation to his daughter about how his wife was found in the bathtub is inconsistent with how neighbors, who testified last week, found the woman's body. Three neighbors testified that Michele MacNeill was found slumped inside the tub, face-up.
Rachel MacNeill, who spoke quietly and cried frequently throughout her testimony Thursday, said her father also insisted that an autopsy be done on Michele "right away."
"He specifically said that he was concerned [about] a police investigation. ... That he didn't want anyone to think he murdered my mother," she recalled.
Defense attorney Susanne Gustin questioned Rachel MacNeill's recollection of events regarding an autopsy, suggesting that it was Rachel who made mentioned the autopsy, not her father. But the woman disagreed.
"My dad repeatedly brought up the autopsy," Rachel MacNeill said.Rachel MacNeill also said that on the day of her mother's death, she went into the garage at her parent's home, and found a bloody, wet pile of clothes and towels, among some of her mother's items that had been kept in the master bedroom of the home as she recovered from plastic surgery, including a hospital bed and small stuffed animals.
She testified that she took a bra, LDS garment top and black shirt that were cut from her mother by paramedics to her father.
"He told me, 'How dare you show me those things? Get rid of it,' " Rachel MacNeill testified.
Instead, the woman said she washed the items and kept them, eventually turning them over to investigators.
Later, at a funeral luncheon for her mother, Martin MacNeill was joking, casual and social, Rachel MacNeill testified.
"He was making jokes about being single, and just laughing," she testified. "It made me sick. I left."
Gustin pointed during cross-examination that while Rachel MacNeill had previously said her father was making jokes at the funeral, she also testified that she saw her father "sad" during the funeral, as well.
Before the jury was brought in on Thursday morning, attorneys argued about whether Ada MacNeill, now 12, would be allowed to testify at the trial.
Defense attorneys had argued before the trial that Ada's testimony was tainted, because she had been asked questions by her sister and legal guardian, Alexis Somers, instead of a child witness expert. They asked to have her testimony barred entirely.
The child was interviewed once at the Children's Justice Center by an expert, but defense attorneys have noted that Somers asked the girl follow-up questions, prompted by Utah County Attorney's Office investigators.
Prosecutors have countered that Somers never suggested answers for her younger sister to give to investigators, and there was no evidence that Ada's testimony was swayed in any way. The questioning from Somers occurred before charges were filed against MacNeill in 2012.
Judge Derek Pullan said he will rule Friday morning on whether the girl can testify.
The state medical examiner has never ruled Michele MacNeill's death a homicide. After an autopsy in 2007, her manner of death was ruled "natural," the result of "chronic hypertension and myocarditis, which are capable of causing acute unexpected arrhythmia and sudden death.
But investigations say Martin MacNeill called the medical examiner multiple times and gave misleading information. In 2010, in a new investigative report, Chief Medical Examiner Todd Grey changed the cause of death to the combined effects of heart disease and drug toxicity. The manner of death was changed to "undetermined."