Justice Mathew Downs said Momoisea set out to make the attack after walking her children to school but had not found Ah'Kee at his home.
She instead went into town and made her plans known.
"You told your pastor's wife you intended to kill Mr Ah'Kee," Justice Downs said.
"She told others what you had said, including your pastor. But as with your daughter two days earlier, no one believed you."
She returned to Ah'Kee's home about 4pm and hid in a converted garage.
When the couple returned home more than two hours later, Momoisea watched them through a gap in the wall.
She lunged at Ah'Kee, stabbing him in the chest.
"You then stabbed Ms Poe-Paila twice," Justice Downs said.
"One of your blows pierced her heart. She fled — and survived. But only through chance and emergency heart surgery."
Momoisea returned to continue the attack on Ah'Kee who fell to the ground and was repeatedly stabbed as he tried to get up.
"It was plainly brutal and callous. And, other things too," Justice Downs said.
"You stabbed Mr Ah'Kee seven times with a large knife, having waited for him in the dark — ready to strike.
"There was little chance he would survive your attack.
"All your blows landed on his chest, back and upper arms."
The Ah'Kee's eldest daughter told the Auckland High Court today that she still struggled to sleep after the death of her lovable hero and "biggest supporter".
"The world seems so empty without my dad."
He was a helpful and caring family man, she said.
"Since that day I found his body, part of me went with him.
"I cannot accept the fact that my father has gone."
It pained her that he had died without any last words or goodbyes, she said.
"You took away so much that I can never get back."
Momoisea's defence counsel John Corby said Momoisea made absolutely no attempt to disguise or hide what she had done.
At the end of her police interview she said she wanted to apologise for what she had done, he said.
"Given the age of my client's parents it is highly unlikely she will see them again.
"When she is deported her situation will be one of an outcast."
Justice Downs said Momoisea killed in anger not in the face of danger.
He said her guilty plea was made "in the face of overwhelming evidence" including her own confession, the eye-witness account made by the survivor and CCTV footage of Momoisea in the area.
However, the plea had still spared the need for a trial in which victims would have made distressing testimony.
"Mr Ah'Kee has six children: a 14-year-old daughter to Ms Poe-Paila and five
other children aged between 24 and seven. You took their father."
Justice Downs said it was significant Momoisea had been banished from her village.
"Because of what you did, your family has engaged in Ifoga, a Samoan cultural
process that involves seeking forgiveness. I have been told your family were, or at
least felt, humiliated and have suffered financially."
Justice Downs took into account her prior good character saying she had been "a stranger" to courts but said it seemed she lacked remorse.
"In your letter to me you say you are very remorseful. The balance of your letter
does not suggest that. Much of it is about how Mr Ah'Kee was to blame.
"And, you say in your letter you are not a murderer. Overall, your letter is consistent with concern about your predicament.
"In reaching this conclusion, I have not overlooked English is very much your second language."
For murder, Momoisea was sentenced to life imprisonment with a minimum non parole period of 14 and a half years.
She was also sentenced to 10 years for the attempted murder of Poe-Paila.
These prison terms would be served at the same time.
