Mrs Mataitonga died after two days in the intensive care unit.
Speaking of her late mother-in-law, the new bride said: "It was such a devastating shock for us all to lose Agnes. Our world has been turned upside down.
"It was supposed to be the happiest day of our lives, our wedding day, such a joyous occasion but in reality it was the opposite."
The couple are now faced with a bill estimated at £20,000 ($39,000) to fly Mrs Mataitonga's body home to Tonga.
The newlyweds, who are from Westminster Park, Chester, had been engaged since last June and are appealing for help with the financial costs.
"The Tongans rarely travel this far and travel insurance is not a common product in the South Pacific, so our relatives also have nothing to contribute to Agnes' repatriation," said Mr Mataitonga.
"We are hoping and praying that we can seek assistance in our sombre and most unexpected task."
Mr Mataitonga expects up to 2000 mourners to attend his mother's funeral.
