Taylor, the Crown says, was suffering from sleep deprivation, headaches, and irritability caused by multiple concussions, around the time Ihaka was developing an ear infection, when he allegedly caused the fatal injuries.
On the second day of the two-week murder trial at the High Court in Christchurch, Stokes, the key witness, took the stand.
She told how Taylor moved in with her in February 2015 when Ihaka was about 10 months old.
Stokes enjoyed an "amazing" relationship with Taylor who Ihaka called "Dad".
Ihaka, who always had a cold, was a "horrible" sleeper, said Stokes who was studying a diploma in business at CPIT.
Taylor did much of the household chores, and despite the side-effects of his concussions, often got up to Ihaka in the night.
Taylor, who was on ACC, also denies assaulting the child on July 2, 2015 - the day before the alleged murder.
Stokes, under questioning from Crown prosecutor Mark Zarifeh, told how Taylor told her the next morning "not to be alarmed but [Ihaka] had hurt himself in the night".
Taylor told her that he had heard a "little bang" in the night and had gone to check on him.
He said he picked up Ihaka, gave him some food, and played games with him "because he had banged his head".
That morning, Stokes - who was 36 weeks pregnant with her second child - noticed a bruise on the right side of his face, from his ear to his jaw, as well as some blood on his sleep sack.
They took him to a local GP who checked him over and found he was developing an ear infection.
That afternoon, Ihaka ate some cheerios - his favourite food - for lunch.
Taylor then slept on the couch while Ihaka did some drawing.
Stokes woke Taylor up for an appointment for a new tattoo around mid-afternoon.
She says while Taylor was out that afternoon, they played puzzles, which was his favourite activity.
Ihaka then had a short sleep before Stokes gave him dinner and got him to sleep shortly before Taylor got home at around 7pm.
Taylor's defence will suggest that during those hours she was alone with Ihaka she could have caused his injuries.
A post-mortem found that Ihaka had suffered 59 separate injuries, including bruising to his forehead, around his eyes and ears, as well as his jaw line, skull, shoulder and arms.
He also had fractured forearms and shoulder blades, compression fractures in his back, and a brain haemorrhage and swelling.
She denied causing the injuries, or ever doing anything to harm her son.
Stokes said she went to bed at about 9pm that night but soon heard Ihaka cry and Taylor trying to settle him.
She got up and saw Taylor inside the cot, with Ihaka on top of him, asleep.
Taylor soon came to bed and Stokes fell asleep.
The next thing she knew was the bedroom light being turned on and Taylor at the doorway telling her "something is wrong with Ihaka".
She ran behind Taylor to Ihaka's bedroom and found him lying on his back, "pale as, blue lips, and not breathing".
Stokes broke down crying in the witness stand as she described Ihaka not breathing, but taking "a big gasp" every "two to five minutes".
She put him into the recovery position.
Stokes said she doesn't remember how but they ended up in the kitchen.
"I was just talking to Ihaka, telling him we would get through this."
A distressing 111 call was played to the jury where Taylor is heard telling the emergency call taker that the couple was in bed when he heard "a loud bang" and that he found his son "not really breathing ... he's going white in the face, blue lips".
A distraught Stokes is heard in the background, saying the boy was bleeding in the mouth.
The call taker talked Taylor through the CPR process until ambulance staff arrived seven minutes later.
Stokes said that from her experiences in watching TV, she thought they only moved patients when they were stable, so she "thought we were on the way to getting him back".
But within an hour, at the hospital, she was told to say goodbye to Ihaka as there was "no chance" of saving him.
Under questioning by Zarifeh, Stokes was today shown a graphic photo of Ihaka's bruised corpse.
Both her and Taylor broke down crying at sight of the image.
Zarifeh talked through the multitude of injuries and asked Stokes if she caused any of them. She replied, no.
Asked if she thought Taylor could ever have been capable of that, she also replied no.
She is now being cross-examined by defence counsel Phil Shamy.
Stokes admitted that Taylor had never been violent with her, and never saw him violent with Ihaka.
The trial, before Justice Cameron Mander, continues this afternoon.
