An Air New Zealand flight from Houston to Auckland was diverted due to a medical emergency.
It is understood a child needed emergency medical treatment.
Diane Tharp said her daughter, Caitlyn Tharp, and her partner were on board flight NZ29.
Caitlyn had just graduated from nursing school and was on her way to New Zealand to celebrate.
Mrs Tharp said: "She messaged us from LA to say a young passenger was having seizures and that was why the flight was turned around.
"Caitlyn offered to help but they had it under control."
A spokeswoman for Air New Zealand confirmed the flight had departed Fiji and was scheduled to arrive in Auckland early this afternoon.
The airline could not confirm reports from passengers that a child had required emergency medical treatment - which forced the aircraft to divert to Los Angeles - citing privacy reasons.
Another passenger, Ross Bolus, contacted the Herald from Nadi, Fiji, where the new cabin crew and pilot were to take over.
Mr Bolus said passengers were still on board.
"Here we are stuck at Nadi Airport. No room at the inn here in Fiji so we have to stay on the plane. The new cabin crew are just wading through the aisles, possibly [with] some extra food," he said.
"The new crew were flown up from Auckland this morning to get us home."
Mr Bolus said he understood a child having epileptic seizures was the passenger "who started this whole adventure".
"Everyone seems quite calm about it though," he said.
It Is understood the ill passenger was left in LA for treatment. The flight briefly stopped in Nadi to change pilots and cabin crew before eventually arriving in Auckland.
Another passenger onboard, Raewyn Rasch, said the flight was diverted to Los Angeles.
Ms Rasch tweeted: "NZ29 from Houston to Auck diverted to LA due to medical emergency. Dumped fuel before landing. Now having to stop in Nandi #longwayhome".
She added: "Yeah for sky couches. Trip home keeps getting longer. No word on what medical emergency caused diversion to LA few hours out from Houston."