The latter charge relates to the mother persuading an older child to lie for her in a written statement he gave to police in which he stated his brother had fallen from a cot.
The Crown's summary of facts read to the court revealed the injury happened after the boy was struck with a forceful slap to his head following a toileting accident.
The victim was knocked unconscious after he hit his head on a nearby doorframe and never regained consciousness. He also had a series of seizures.
While the boy's father did not witness the assault, he understood who was responsible.
After giving his son pain relief and placing some ice on the injury, he put the boy to bed.
The victim remained in a state of unconsciousness for more than two days without any significant medical treatment - he did not speak, eat or drink and had several further seizures.
Some 50 hours later the mother rang her social worker and asked to be taken to a medical centre, but the social worker immediately took her and her gravely ill son to Tauranga Hospital.
Doctors assessed the boy as needing immediate care to save his life.
A CT scan revealed a sub-dural haemorrhage and the boy was transferred to Starship Hospital.
The mother, who faces a lengthy jail sentence, showed little emotion as Crown prosecutor Heidi Wrigley read out the summary of facts, apart from bowing her head a couple of times.
The mother repeatedly lied to medical staff and the social worker about her son's symptoms and how the injury was caused.
She initially claimed her son hit his head on a metal bar at a park, then added while at home the next day he fell from the couch and the same day also fell off the bed.
At Starship the mother told doctors her son hit his head on a wooden platform at the park, but was able to play all day (two days after assault) until he fell ill with a fever.
The father claimed his son had been up watching TV on the day he was hospitalised.
Six days after the assault the mother admitted to police she had earlier lied but then claimed her younger child had hit the victim with a piece of firewood.
Two days later when she tried to feed her son his eyes were "fixed" and he was non-responsive.
She told police she would have taken her son to the hospital but had no transport, no phone and believed she would have had to wait a long time for treatment.
The mother, who faces a lengthy jail sentence, showed little emotion as Crown prosecutor Heidi Wrigley read out the summary of facts, apart from bowing her head a couple of times.
Judge Robert Wolff remanded the couple in custody pending sentence on December 15.
